Astrakhan State Technical University

Department of Neft and Gas Geology

LECTURE COURSE

by discipline:

Geological foundations of the development of oil, gas and gas condensate fields

Introduction

The lecture course "The Geological Basics of the Development of Oil, Gas and Gas-condensate deposits" consists of three interrelated parts:

1.Basics of oil and gas pool geology

2.Counting stocks and evaluation of hydrocarbon raw materials

.Geological foundations of the development of oil and gas fields.

The main objective of the study of this discipline is the geological support for the efficient development of oil and gas.

In the first part, it was shown that oil and gas prepared geology is a science that is engaged in the study of oil and gas deposits in a static and dynamic condition as sources of hydrocarbon raw materials.

Oil and gas prepared geology as science originated at the beginning of the last century (1900) and passed a long path of development. This path is divided into several stages that differ around the issues solved, methods and means of their solution. The modern stage, which began at the end of the 40s of the twentieth century, is characterized by the use of methods of impact on productive layers when developing oil deposits. The results of studies of oil and gas prepared geology serve as a geological basis for the design and regulation of hydrocarbon deposits. Oil and gas prepared geology considers the deposit of oil and gas before the development of the development as a static geological system consisting of interrelated elements:

natural reservoir, a certain form with a specific void volume;

reservoir fluids;

thermobaric conditions.

The developed hydrocarbon deposit is considered as a comprehensive dynamic system, changing its state in time.

In the second part of the benefit, the definitions of groups and categories of reserves and resources of oil, gas and condensate are given. Details considered methods of reserves and estimating oil resources, condensate gas and passing components. To count the reserves of oil and gas, it is necessary to comprehensively geological study of the field, with which the deposits of oil and gas and knowledge of the characteristics of their location are associated.

The third part provides the basic concepts of geological and commercial support for the development of oil and gas deposits. The development systems of multidimensional oil and gas fields and a separate operational facility are considered, the development of oil fields with maintaining reservoir pressure are also given, the methods of geological and commercial control over the process of developing hydrocarbon deposits and methods for increasing the oil recovery of the formation are considered in detail.

The course ends with the topic: "The protection of the subsoil and the environment in the process of drilling wells and the development of hydrocarbon deposits." Thus, the main tasks of this discipline are as follows:

detailed study of hydrocarbon deposits

geological rationale for choosing development systems

control of the development of oil and gas deposits in order to justify and choose measures to manage development processes

summary of the experience of developing oil and gas fields

planning oil production, gas, condensate;

counting oil, gas, condensate and passing components;

security and the environment in the process of drilling wells and operation of hydrocarbon deposits.

Each oil, gas and condensate deposit is introduced into the development in accordance with the project document drawn up by a specialized research organization and providing that system of development, which is most rational for this field with nationwide positions.

The development of oil (gas) deposits is a complex of works carried out to control the process of movement of the reservoir fluids on the reservoir to the slaughterhouses of operational wells. The development of oil (gas) deposits includes the following elements:

Ø the number of wells for deposits;

Ø placing wells for deposits;

Ø order (sequence) of input of wells to operation;

Ø well mode;

Ø balance of Plast Energy;

The development system of oil deposits (gas) is swelling the deposits of operational wells according to a specific scheme and the adopted plan, taking into account the activities on the impact on the reservoir. The development system is called rational when it is used with the most complete use of reservoir energy and the use of measures for the effects on the reservoir ensures maximum extraction of oil and gas from the subsoil as soon as possible with minimal costs, taking into account the specific geological and economic conditions of the region.

The development of the oil and gas industry in Russia has more than a century of history. Up until the mid-40s, the X1x century, the development of oil fields was carried out only using the natural energy of deposits. It was associated with a not enough high level of technology and development technology, as well as with the lack of objective prerequisites for the fundamental change in this approach to development.

From the middle of the 40s, as a result of the discovery of new oil and gas areas, the development of the oil industry is associated with the development of platform type deposits with large size of the area of \u200b\u200boil and a significant depth of the occurrence of productive reservoirs and an ineffective natural mode - a strengthen pressure, quickly turning into a dissolved gas mode. Russian scientists and production workers in a short time justified theoretically and proved in practice the need and the possibility of applying fundamentally new development systems with an artificial introduction into productive oil layers of additional energy by injection into them in them.

The next step of scientific and technological progress was the search for processes ensuring further improvement in the efficiency of oil deposits. In recent years, scientific and engineering idea has been working on creating ways to improve the efficiency of flooding. At the same time, it is sought and tested, industrial testing and introducing new methods of exposure to oil layers, which are based on fundamentally new physicochemical processes of oil displacement from breed collectors.

The development of gas deposits, taking into account the high efficiency of their natural regimes to the present, is carried out using natural energy without artificial impact on the reservoir.

In the last period, gas-condensate fields play a major role in the balance sheet of hydrocarbons.

And here, one of the most pressing tasks are the search for economically expedient methods for the development of gas condensate deposits that prevent the loss of condensate in the formation.

Section 1: "Methods for studying the geological structure of the subsoil and deposits of hydrocarbons on commercial areas"

Chapter 1. Geological Observations and Research when drilling wells

The deposits of HC are always isolated from the day surface and are located at different depths - from several hundred meters to several kilometers - 5.0-7.0 km.

The main goal of geological observations for the process of drilling wells is to study the geological structure of deposits and individual productive horizons and saturated with these horizons of fluids. The more fully this information will be better, the better the project of the development of the deposit.

Behind the process of drilling wells should be made thorough geological control. At the end of the borehole, the geologist should receive the following information about it:

the geological section of the well, litology of the work passed;

position in the context of the reservoir breeds;

the nature of the saturation of breed-collectors than they are saturated, what a reservoir fluid

technical Status of Wells (Design of Wells, Distribution by Pressure Tank, Temperature)

Especially thorough geological control should be carried out when drilling exploration wells, on which the drilling of operational wells for oil and gas will be founded.

Methods for studying cuts of roaming wells are divided into 2 groups:

1.direct methods

2.indirect methods

Direct methods allow us to directly receive information about the section of the lithology of rocks, the real composition, the position of collectors and their saturation.

Indirect methods provide information on the context of wells on indirect features, namely, by the relationship of their physical properties with the same characteristics, as resistance to the passage of electric current, magnetic, elastic.

Direct methods are based on study:

samples of rocks selected from the well in the process of drilling (core, sludge, lateral primeros)

selection of fluid samples with passing and stationary testing.

sampling of reservoir fluid when testing in the operational column

gas carotout

observation of complications in the process of drilling (the collar walls of the well, absorption of the drilling fluids, manifestation of the reservoir fluid)

Indirect methods make it possible to judge the real composition of the cut of wells, collector properties, the nature of the saturation of breed-collectors by the reservoir fluid on indirect features: natural or artificial radioactivity, the ability of the breed of electric current, acoustic properties, magnetic, thermal.

Studying Core

Curne material is the main information about the well.

The choice of the drilling interval with the selection of core depends on the geological tasks set.

On the newly poorly studied fields, when drilling the first wells, it is recommended to produce a solid selection of core together with complexes of geophysical studies. In the field, where the upper part of the cut has been studied, and the bottom is still subject to a study, in the studied interval of Kern, it is necessary to select only in the contacts of the retinue, and in an unexplored interval - to produce a solid selection of core (see Fig. 1)

In the operational wells, Kern is not selected and all observations are based on the information of logging and observations of the drilling process. In this case, Curne is selected in the productive horizon for its detailed study.

When studying the core, you need to get the following well information:

availability of features of oil and gas

the material composition of the breed and their stratigraphic affiliation

collective properties of breeds

structural features of breeds and possible conditions for their location

Samples of rocks that are sent to the laboratory to study the content of HC, paraffinate (wrapped in gauze and are immersed several times in the melted paraffin, allowing each time to harden the paraffin that has impregnated with gauze). The reinforced samples are then placed in metal cans with flat lids. Samples are shifted with cotton wool or soft paper and sent to the laboratory for the study. The remaining part of the core is handed over to the core.

Signs of oil and gas in cores should be previously studied on the drill on fresh samples and breaks and then in more detail in the fishing management laboratory.

Fig.1 - A - drilling without a core selection; b - drilling with selection of core

The borehole intervals with the selection of core are determined by the purpose of drilling and the degree of exploring the cut. All deep wells are divided into 5 categories: - support, parametric, search, exploration, operational.

Supported wells are clogged to study the general geological structure in the territories unexplored by deep drilling. The core selection is uniformly throughout the wellbore. In this case, the penetration with the selection of core ranges from 50 to 100% of the total depth of wells.

Parametric wells are clogged to study the geological structure and prospects of oil and gas potential of new territories, as well as to link geological and geophysical materials. The penetration with the selection of the core is at least 20% of the total depth of the well.

Search wells are placed in order to search for oil and gas deposits. The selection of core here is produced in the interval of the occurrence of productive horizons and contacts of various stratigraphic divisions. With the selection of the core there is no more than 10-12% of the depth of wells.

Exploration wells are clogged within the area with an established oil and gas industry in order to prepare a deposit for development. Curne is selected only in the range of productive horizons within 6-8% of the depth of the well.

Operating wells are painted in order to develop oil and gas deposits. Kern, as a rule, is not selected. However, in some cases, core selection is practiced to study the productive reservoir at 10% of wells uniformly located in the area.

The intervals with the selection of core pass with special groups - core, which in the center of the bit are left not a stubborn breed, called core and raise it to the surface. The stubborn part of the rock is called sludge, which is endowed on the surface of the jet of the drilling fluid during the drilling process.

Selection of breed samples with side grounds

This method is used when the core could not be selected in the planned interval. In addition, even when, according to the result of geophysical studies, after the end of drilling, the wells identified horizons of interest from the point of view of oil and gas, but this interval is not covered with core. With the help of lateral grinding from the wall of the well, a sample of rock is selected. Currently, 2 varieties of samples are applied:

1.shooting side grounds

2.drilling side grounds

The principle of operation of the shooting primeros: on the pipes descends against the interval of the garland of cartridges that interests us. When exploding, the sleeves are crashed into the wall of the well. When lifting the tool of the sleeve on steel leashes with a trapped rock from the wall of the well rises upstairs.

Disadvantages of this method:

we get crushed breed

sample small volume

in the hard breed of the battle is not impaved

the breed is poured

Drilling side grounds - imitation of horizontal drilling, we obtain small volume samples.

Selection of sludge

In the process of drilling, the chisels destroy the rock and the jet of flushing fluid fragments of rocks are taken to the surface. These debris, rock particles are called sludge. They are selected on the surface, they are laundered from the drilling fluid and carefully studied ie. Determine the real composition of these debris. Research results are applied to the schedule according to the depth of the sludge. This diagram is called a slotmogram (see. 2) in the drilling process, the sludge is selected in all categories of wells.

Fig. 2 Slumogram

Geophysical well research methods Learn independently when learning the GIS course.

Geochemical research methods

Gas carotout

In the process of drilling well, the drilling solution washes the productive reservoir. Oil and gas particles fall into the solution and are taken out with it to the surface, where the special sampler is made of degassing of the drilling fluid, the content of light HC and the total content of hydrocarbon gases is studied. The results of the study are applied to a special gas logging diagram (see Fig. 3).

Fig.3 Gas logging diagram

If in the drilling process, the presence of a productive reservoir is established, the gas sample with chromatograph is investigated for the content of individual components directly on the drilling well.

Mechanical carotor

The speed of the penetration is studied, the time spent on drilling 1M is recorded and the results are applied to a special form (see Figure 4).

Fig. 4. Mechanical logination form

Caverneometry

Cavernometry -continuous definition of a well diameter using a kavernomer.

In the process of drilling, the diameter of the well differs from the diameter of the bit and changes depending on the lithological type of rocks. For example, in the interval of the permeable sandy rocks, a narrowing occurs, a decrease in the well diameter, as a result of the formation of a clay crust on the walls of the well. In the range of clay rocks, the opposite is observed, an increase in the diameter of the well is observed compared to the diameter of the bit as a result of the saturation of clay rocks by the drilling fluid filtration and the further collapse of the well walls (see Fig. 5). In the interval of carbonate rocks, the well diameter corresponds to the diameter of the bit.

Fig. 5. Increase and decrease the diameter of the well depending on the lithology of rocks

Observations of the parameters of the drilling fluid, oil and gas production

In the process of drilling well, the following complications may occur:

the collar of the walls of the wells, which leads to the grab of the drilling instrument;

absorption of the drilling fluid, up to its catastrophic care, when opening the zip zone zones;

drying the drilling fluid, reduce its density, which can lead to an oil or gas emission.

Passing and stationary testing of the productive reservoir

There are associated and stationary testing of the productive reservoir.

The passing testing of the productive reservoir lies in the selection of samples of oil, gas and water from productive layers in the process of drilling with special devices:

flash Obligator on a logging cable OPK

bearing Tests on Drill Pipes - Kii (Test Tool Kit)

Stationary testing is made at the end of the well drilling.

As a result of the testing of the formation of the following information:

The nature of the reservoir fluid;

Information on the formation pressure;

Position of VCK, GVK, GNA;

Information on the permeability of the breed - collector.

Design documentation for Construction of Wells

The main document for the construction of wells is a geological and technical outfit. It consists of 3-parts:

geological part

technical part

The geological part contains the following well information:

design cut of the well

age of breeds, depth of occurrence, angles of fall, fortress

possible complications intervals, core selection intervals.

The technical part provides:

drilling mode (load on chisel, drilling pump performance, rotor speed)

depth of the descent of columns and their number, diameter

height of lifting cement for column, etc.

Chapter 2 Methods of geological processing of materials drilling materials and the study of the geological structure of the deposit

The geological processing of well drilling materials makes it possible to build a field profile and structural maps on the roof of the productive reservoir, allowing to obtain a complete picture of the structure of the field. For a detailed study of all issues of the structure of the field, it is necessary to carry out a thorough correlation (comparison of well-cuts).

The correlation of fusion cuts is to highlight the reference formations and determine the depth of their occurrence in order to establish a sequence of occurrence of rocks, identifying the reservoirs of the same name to trace the change in their thickness and lithological composition. In oil fields, the overall correlation of cuts of wells and zonal (detailed) are distinguished. With a general correlation, the sections of wells are compared from the well of the well to the bottom of one or more horizons (referees) see Figure 6.

Detailed (zonal) correlation is carried out for a detailed study of individual reservoirs and packs.

The correlation results are presented in the form of a correlation scheme. The reper (labeling horizon) is a reservoir in the section of a well, which is dramatically different in its characteristics (real composition, radioactivity, electrical properties, etc.) from the above and underlying formations. He must:

easy to be in the context of wells;

attend the context of all wells;

having a small but constant value.

Fig. 6. Repeper surface

During the zonal correlation for the reference surface, the roof of the productive reservoir is taken. If it is blurred - the sole. If it is blurred, you choose any reservoir weathered within the area of \u200b\u200bthe reservoir.

Drappiness of the deposits of the field - typical, medium-neural, consolidated

When performing a total correlation, we obtain information about the formation of rocks and their thickness. This information is necessary for building a deposit. On such a section, there is averaged characteristic of rocks, their age and thickness.

If the vertical thickness of the layers is used, the incision is called a typical cut. Such cuts are on commercial areas. At the exploration areas, medium-class cuts are compiled, where true (normal) layer thickness are used.

In the case when the incision of the field varies significantly in the area - consolidated cuts are built. When drawing up a lithological column on a consolidated section, the maximum thickness of each formation is used, and the maximum and minimum value is given in the column "thickness".

Drawing up a geological profile section of the deposit

Geological profile section - a graphic image of the structure of the subsoil by a certain line in the projection on the vertical plane. Depending on the position on the structure, profile (1-1), transverse (2-4) and diagonal (5-5) cuts are distinguished.

There are certain rules for the orientation of the profile line in the drawing. On the right is the north, east, northeast, southeast.

Left - South, West, Southwest, Northwest.

To build a profile section of the deposit, the scale is most often used 1: 5000, 1: 10000, 1: 25000, 1: 50000, 1: 100000.

In order to avoid distortion of the angles of falling breeds, the vertical and horizontal scales are accepted the same. But for clarity, the image is vertical and horizontal scales are accepted different. For example, the scale is vertical 1: 1000, and horizontal 1: 10,000.

If the wells are twisted - first we build horizontal and vertical projections of twisted wells, we apply vertical projections to the drawing and build a profile.

Sequence of building a profile section of the deposit

The sea level line is conducted - 0-0 and lay the position of the well on it. The position of the 1st well is chosen arbitrarily. Through the obtained points spend the vertical lines, on which the altitudes of the wellhead wells are deposited on the profile scale. We connect the mouths of the wells with a smooth line - we get a terrain.

Fig. 9. Profile section of the deposit

From the mouth of the well, we build well trunks before slaughter. Projections of twisted trunks pierce the drawing. On the wellblock of wells, we put the depth of the stratigraphic horizons, the elements of the occurrence, the depth of the discontinuous disorders, which are presented first.

Building a structural card

Structural card is a geological drawing that reflects in horizontals underground roofing or soles of any single horizon, in contrast to the topographic map showing horizontally terrestrial surface surface, in the structure of which horizons of different ages can participate.

The structural card gives a clear idea of \u200b\u200bthe structure of the subsoil, provides accurate design of operational and exploration wells, facilitates the study of oil and gas deposits, the distribution of reservoir pressures on the area of \u200b\u200bthe deposit. An example of building a structural map is shown in Figure 10.

Fig. 10. An example of building a structural card

When building a structural map for the basic plane, the sea level is usually taken from which the horizontal (isogenes) of the underground relief is counted.

The marks below sea level are taken with a minus sign, above with a plus sign.

Equal in height gaps between isoizes called cross section of isoips.

In commercial practice, the following methods of building structural maps are usually applied:

the method of triangles - for undisturbed structures.

the method of profiles - for strongly disturbed structures.

combined.

Construction of a structural map by the method of triangles is that wells are connected by lines, forming a system of triangles, preferably equilateral. Then there are interpolation between the opening points of the formation. We connect the same names - we get a structural map.

The absolute point of the opening point of the reservoir is determined by the formula:

+ AO. \u003d + Al-,

A.O.-the absolute mark of the opening point of the reservoir is the distance vertically from the sea level to the opening point of the reservoir, m.

Al - Altituda of the mouth of the well - the distance vertically from the sea level to the mouth of the wells, m.

l. -Engube opening of the formation - the distance from the mouth of the wells to the opening point of the reservoir, m.

ΣΔ l. - amendment to the curvature of wells, m.

Figure 11 shows various opening options:

Fig. 11. Various opening options

Terms of oil, gas and water in depths

For the implementation of the rational system of development and organization of efficient operation of oil and gas reservoirs, their physical and collector properties, the physicochemical properties of the reservoir fluids contained in them, the conditions for their distribution in the formation, hydrogeological features of the formation are needed.

Physical properties of rocks - collectors

Productive layers of oil deposits containing hydrocarbons are characterized by the following main properties:

porosity;

permeability;

richness of breeds of oil, gas, water in various conditions of their location;

granulometric composition;

molecular surface properties when interacting with oil, gas, water.

Porosity

Under the porosity of rocks, the presence of emptiness in it (pores, cavern, cracks) is understood. Porosity determines the ability of the breed to accommodate a plastic fluid.

The porosity of the pore volume of the sample to its volume, expressed as a percentage.

p \u003d V.p / V.about *100%

Quantitatively porosity is characterized by a porosity coefficient - the ratio of the pore volume of the sample to the volume of the sample in the fractions of the unit.

k.p\u003d V.p / V.about

Various rocks are characterized by various porosity values, for example:

clay shale - 0.54 - 1.4%

clay - 6.0 - 50%

sands - 6.0 - 52%

sandstones - 3.5 - 29%

limestones, Dolomites - 0.65 - 33%

The following types of porosity are distinguished in the field practice:

the total (absolute, physical, complete) is the difference between the volume of the sample and the volume of its grain components.

open (saturation porosity) - the volume of all pores and cracks in which liquid or gas penetrates;

effective - volume of pores saturated with oil or gas minus the content of bound water in the pores;

The effectiveness coefficient of porosity is the product of the coefficient of open porosity on the coefficient of oil and gas saturation.

Carbonate rocks are productive at porosity equal to 6-10% and higher.

The porosity of sand breeds varies within 3 - 40%, mostly 16-25%.

Porosity is determined by laboratory analysis of samples or according to the results of GIS.

Permeability of rocks

Permeability of rock [to]- The ability to skip the plastic fluid.

Some rocks, such as clay, have high porosity, but low permeability. Other limestone - on the contrary - low porosity, but high permeability.

In oilfield practice, the following types of permeability distinguish:

absolute;

efficient (phase);

relative;

Absolute permeability is the permeability of the porous medium when a single phase (oil, gas or water or water) is moved. As an absolute permeability, the permeability of rocks, determined by gas (nitrogen) - after extraction and drying the rock to constant weight. Absolute permeability characterizes the nature of the medium itself.

Phase permeability (efficient) is the permeability of the breed for this fluid in the presence and movement in the pores of multiphase systems.

The relative permeability is the ratio of phase permeability to absolute.

When studying the permeability of rocks, the formula of the linear law of filtration of Darcy is used, according to which the rate of filtration of the liquid in the porous medium is proportional to the pressure drop and inversely proportional to the viscosity of the fluid.

V \u003d Q / F \u003dkΔp./ μL ,

Q.- volume flow of fluid through the breed per 1 sec. - M. 3

V. -Shetability of linear filtering - m / s

μ - dynamic viscosity of fluid, n s / m2

F.- filtration area - m.2

Δp.- pressure drop at the length of the sample L, MPa

k.-caffefficient of proportionality (permeability coefficient) is determined by the formula:

K \u003d QML /FΔp.

The units of measurement are as follows:

[L] -M [F] -M2 [Q] -M3 / C [p] -n / m2 [ μ ] -NC / m2

With all the values \u200b\u200bof the coefficients of equal units, the dimension K is m2

Physical meaning dimension k.this is the area. Permeability characterizes the size of the cross-section of the channels of the porous medium, along which filtering the reservoir fluid is carried out.

In the fishery to assess the permeability, the practical unit is used - darcy- which is 10 12 Once less than k \u003d 1 m2 .

Per unit B. 1d Take the permeability of such a porous medium, when filtering through a sample of which area 1 cm2 lena 1 cm With pressure drop 1 kg / cm2 Fluid consumption viscosity 1p. (Santi Poise) is 1 cm3 /from. Value 0.001 D.- called money.

Oil - and gas-bearing layers have the permeability of about 10-20 MD to 200 MD.

Fig. 12. The relative permeability of water and kerosene

From fig. 12, it can be seen that relative permeability for kerosene Cook- quickly decreases with an increase in the water saturation of the formation. When achieving water protection Kv. - up to 50% relative permeability coefficient for kerosene Cook Reduced to 25%. With increasing Kv. up to 80% Cook It is reduced to 0 and pure water is filtered through a porous medium. The change in the relative permeability for water occurs in the opposite direction.

Terms of oil, gas and water in deposits

Oil and gas deposits are located in the upper parts of the structures formed by porous and overlapping their impermeable rocks. (Tires). These structures are called traps.

Depending on the conditions of the occurrence and the quantitative ratio of oil and gas, the deposits are divided into:

pure gas

gas condensate

gas connecting (with gas cap)

petroleum with dissolved gas.

Oil and gas are located in the deposits, respectively, their densities: gas in the upper part lies below - oil, and even lower - water (see Figure 13).

In addition to oil and gas in the oil and gas parts of the reservoirs, water is also contained in the form of thin layers on the pore walls and subcapillary cracks held by capillary pressure. This water is called "Related" or "residual". The content of "bound" water is 10-30% of the total volume of pore space.

Fig.13. Oil, gas and water distribution in deposits

Value elements oil Gaza.:

waterproof contact (BNK) - the boundary between the oil and water parts of the deposit.

gas phone contact (GNA) - the boundary between the gas and oil parts of the deposit.

gas-breeding contact (GVK) - the boundary between the gas-saturated and water-saturated parts of the deposit.

the outer contour of the neboles is the intersection of the VNK with the roof of the productive reservoir.

the inner contour of the nebolesality is the intersection of the VNK with the sole of the productive reservoir;

the round zone is part of the deposits of oil between the external and internal contours of the oil.

The wells drilled within the inner contour of the neboles, open the oil reservoir for the entire thickness.

The wells drilled within the round zone are opened in the upper part - the oil-saturated formation, below the VNK - a water-saturated part.

The wells drilled behind the profiles of the outer contour of the nestlessness reveal the water-saturated part of the reservoir.

The coefficient of water saturation is the ratio of the volume of water in the sample to the thorest of the sample.

K.in\u003d V.water/ V.pore

The oil saturation coefficient is the ratio of the volume of oil in the sample to the thorest of the sample.

TOn.\u003d VNF / V

Between these coefficients, there is the following dependence:

TOn. + K.in=1

Thickness of productive reservoirs

In oilfield practice, the following types of thicknesses of productive reservoirs are distinguished (see .Ris.14):

total thickness of the layer h.common - The total thickness of all commissions - permeable and impenetrable - the distance from the roof to the soles of the formation.

effective thickness h.eF - Total thickness of porous and permeable propelurs, for which fluid movement is possible.

efficient oil - or gas-saturated thickness H.eFn-us - Total thickness of fasteners saturated with oil or gas.

h.common- (in the total thickness)

eF\u003d H.1 + H.2EFn-nos.\u003d H.1 + H.3

Fig. 14 laughter thickness of productive reservoirs

To study the patterns of changes in thickness, a map is compiled - general, efficient, and efficient oil and gas-saturated thickness.

The lines of equal values \u200b\u200bof thicknesses are called isopapitov, and the map is a card isopahite.

The method of constructing is similar to the construction of a structural map by the method of triangles.

Thermobaric conditions for subsoil oil and gas fields

Know the temperature and pressure in the depths of oil and gas fields are necessary in order to properly approach the solution of issues with both scientific and nationally and economic importance:

1.formation and placement of oil and gas deposits.

2.determination of the phase state of hydrocarbon clusters at large depths.

.issues of drilling technology and injection of deep and ultra-deep wells.

.development of wells.

Temperature in the depths

Numerous temperature measurements in idle wells are noted that with depth temperature increases and this increase can be characterized by a geothermal step and a geothermal gradient.

With an increase in the depth of the occurrence of productive reservoirs, the temperature rises. Changing the temperature per unit depth of NED. geothermal gradient. Its value fluctuates in the range of 2.5 - 4.0% / 100 m.

The geothermal gradient is the increment of temperature per unit length (depth).

gRAD T \u003d T2 -t.1 / H.2 -H1 [ 0 Cm]

Geothermal stage [g] - this is the distance to which you need to deepen so that the temperature rose to 10 FROM.

G \u003d H.2 -H1 / t.2 -t.1 [m /0 FROM]

Fig. 15. Change temperature with depth

These parameters are determined by measurements of temperatures in idle wells.

Measurements of temperature with depth are carried out either by electrothermometer throughout the well barrel, or a maximum thermometer for scientific purposes.

The maximum thermometer shows the maximum temperature at a depth to which it is lowered. The electrothermometer registers a continuous recording of the temperature on the wellbore when lifting the instrument.

To obtain true temperatures, the well breeds should be located at rest for a long time, not less than 25-30 days so that natural thermal mode is installed, drowning. According to the results of measurements of temperatures, thermograms are constructed - the temperature dependence curves from the depth. Using these thermograms, you can determine the geothermal gradient and stage.

On average, the geothermal gradient has a geothermal gradient for 2.5-3.0 0C / 100m.

Reservation pressure in the depths of oil and gas fields

Each underground reservoir is filled with oil, water or gas and has the energy of the plastic water system.

Plastic energy is the potential energy of the reservoir fluid in the field of gravity of the Earth. After the well is drilled, there is a violation of equilibrium in the natural water water system: the potential energy goes into the kinetic and spent on moving fluids in the formation to the collection of operational wells and rise them to the surface.

The formation measure is the reservoir pressure - this is the pressure of fluid or gas located in the formation - collectors under conditions of natural occurrence.

On oil and gas fields, reservoir pressure (P pL ) with depth increases for every 100m depth of 0.8 - 1.2 MPa, i.e. about 1.0 MPa / 100m.

Pressure that is equalized by a pillar of mineralized water with density ρ \u003d 1.05 - 1.25 g / cm 3 (103 kg / m 3) It is called normal hydrostatic pressure. It is calculated so:

RN.G. \u003d H.ρ in/ 100 [MPa]

N-depth, m.

ρ in- water density, g / cm3 , kg / m3 .

If a ρ in We accept equal to 1.0, then such pressure is called conditional hydrostatic

Conditional hydrostatic pressure is such a pressure that is created by a freshwater post with a density of 1.0 g / cm 3 Height from the mouth of the well before slaughter.

Ru.G.\u003d N / 100 [MPa]

Pressure that is balable with flushing fluid with density ρ j. \u003d 1.3 g / cm 3 and more, a height from the mouth to the bottom of the well is called superhidrostatic (SGPD) or aell-high reservoir pressure (AVAP). This pressure is 30 and more than% exceeds the conditional hydrostatic pressure and by 20-25% is normal hydrostatic.

The ratio of the AvPA to a normal hydrostatic is called the anomalistic coefficient of reservoir pressure.

TObut\u003d (R.AVAP/Rn.G..) >1,3

The pressure below hydrostatic is an abnormally low reservoir pressure (ANPD) - it is a pressure that is equalized by the flushing fluid post with a density of less than 0.8 g / cm 3. If ka< 0,8 - это АНПД.

One of the most important characteristics of the formation is mountain pressure - this is a pressure that is a consequence of the total effect on the reservoir of geostatic and geotectonic pressures.

Geostatic pressure is a pressure that has a mass of the threads of the breeds on the reservoir.

Rg.E.= Hρ.p / 100 [MPa]

Where, ρ p \u003d 2.3 g / cm 3 - average density of rocks.

Geotectonic pressure (voltage pressure) is a pressure that is formed, formed in the formation as a result of continuously intermittent tectonic movements.

Mountain pressure is transmitted by the rocks themselves, and inside the rocks - their skeleton (grains, layer layers). In natural conditions, reservoir pressure opposes mountain pressure. The difference between geostatic and reservoir pressure is called sealing pressure.

RuPL\u003d R.g.E. - RpL

In commercial practice, under the reservoir, the pressure is understood as pressure at some point of the reservoir, which is not subject to the influence of the depression of neighboring wells depressed (see. 16) depression on the reservoir Δ P. calculated by the following formula:

Δ P \u003d P.pL - P.baby ,

where, PLL-plastic pressure

Pzab -The leaving for a working well.

Fig. 16 Distribution of reservoir pressure during working wells

Primary reservoir pressure P.0 - This is the pressure measured in the first well, starting the reservoir before selecting the layer of any noticeable amount of fluid or gas.

The current reservoir pressure is the pressure measured on a specific date in the well, in which relative statistical equilibrium has been established.

To eliminate the influence of the geological structure (the depth of measurement) on the magnitude of the reservoir pressure, the pressure measured in the well is recalculated on the middle of the oil or gas content, on the middle point of the deposit volume or on the plane coinciding with the BNK.

In the process of developing oil or gas deposits, the pressure changes continuously, when monitoring the development of pressure, the pressure is periodically measured in each well.

To study the nature of the change in pressure within the area of \u200b\u200bthe deposits, build pressure maps. The lines of equal pressure are called source, and cards - Maps areobar.

Fig. 17. Graph of changes in pressure in time by wells

Systematic control over the change in reservoir pressure allows us to judge the processes occurring in the formation and regulate the development of the field as a whole.

The reservoir pressure is determined using well pressure gauges descended into a well on a wire.

Fluids and gas in the reservoir are under pressure, which is called reservoir. From the magnitude of the reservoir pressure P.pL- The supply of plastial energy and the properties of liquids and gases in reservoir conditions depends. P.pL Determines the reserves of gas deposits, flow rate and conditions of exploration of deposits.

Experience shows that P.0 (initial reservoir pressure) measured in the first drilled well depends on the depth of the deposits and can be approximately defined by F-le:

P \u003d. Hρg. [MPa]

H- depth of the deposits, m

ρ- liquid density, kg / m 3

g-acceleration of free fall

If the well fountains (transfers), p pL Determined by the formula:

P. pL =Hρg. + P (pressure on mouth)

If the fluid level does not reach the mouth

P. pL \u003d H. 1ρg.

H. 1- the height of the pole of the liquid in the SLE, M.

Fig. 18. Determination of the above reservoir pressure

In the gas deposit or gas part of the oil reservoir, the reservoir pressure is almost the same throughout the volume.

In oil deposits, the reservoir pressure in different parts is different: on the wings - the maximum, in the edge-melted. Therefore, the analysis of the change in the reservoir pressure during operation of the deposit is hampered. It is more convenient to attribute the values \u200b\u200bof the reservoir pressure to one plane, for example, to the plane of water-oil contact (BNK). The pressure referred to this plane is called the above (see cris.18) and is determined by the formulas:

P.1Pr \u003d P.1 + H.1 ρg.

P.2Pr \u003d P.2 - H.2 ρg.

Physical properties of oil, gas and water

Gaza deposit gases are called natural gases, and gases extracted with oil - oil or passing.

Natural and oil gases consist mainly from the limiting hydrocarbons of a number with n. N. 2N + 2. : Methane, ethane, propane, butane. Starting with Pentane (C 5H. 12) And above - these are fluids.

Often, hydrocarbon gases in their composition contain a hydrocarbon (CO 2, hydrogen sulfide H. 2S, nitrogen N, helium he, argon, ar, mercury and mercaptan pairs. Content Co. 2 and H 2S sometimes reaches tens of percent, and the remaining impurities - the share of percent, for example, in a plastic mixture of AGCM, carbon dioxide content is 12-15%, and hydrogen sulfide is 24-30%.

The molecular weight (M) - hydrocarbon gases is determined by the formula:

M \u003d Σm.i.Y.i.

M.i.- molecular weight of the i -to component

Y.i.- the fraction of the i -to component in the mixture in volume.

The density is the ratio of the mass of the substance to the occupied volume.

ρ \u003d M / V [kg / m3 ].

The density is in the range of 0.73-1.0 kg / m 3. In practice, the relative gas density is used - the ratio of the mass of this gas to the mass of the same volume.

Relative densities of various gases are shown below:

Air - 1.0ch. 4 - 0,553N. 2 - 0,9673c. 8H. 6 - 1,038Co. 2 - 1,5291c. 3H. 8 - 1,523H. 2S - 1,1906c. 4H. 10 - 2,007

To move from volume under normal conditions to the volume of the same amount occupied in reservoir conditions, the volumetric coefficient of reservoir gas V, the volume that would occupy 1M 3 gas in reservoir conditions.

V \u003d V.0 Z (TP.0 / T.0 * P)

Where, V.0 - gas volume under normal conditions at initial pressure P. 0 , and temperature T.0 .

V is the volume of gas at the current pressure P and temperature that is the coefficient of the gas compressibility.

Volumetric Factor Gas V is within 0.01-0.0075

Gas viscosity - gas property resist the movement of some particles relative to others. In the system system, dynamic viscosity is measured in MPa * C (mile-paskal per second), for example, the dynamic viscosity of water at T 0 200C is μ \u003d 1 MPa * p. Gas field gas viscosity ranges from: 0.0131- 0.0172 MPa * p.

The viscosity of the formation mixture of AGCM is 0.05 - 0.09 MPa * p.

Solubility of gases in oil

The volume of one-component gas dissolving in unit volume of fluid is directly proportional to pressure

V.g./ V.j. = αp.

Where, V. g. - Volume of dissolving gas

V. j. - Liquid volume

Basics of commercial geology and development of oil and gas fields 1 page

Oil and gas industry geology (NGPG) is the Geology industry, which is engaged in detailed study of fields and deposits of oil and gas in the initial (natural) state and in the process of developing to determine their nationality and rational use of subsoil.

The main objectives of NGPG are as follows:

Fishing and geological modeling of deposits;

Structuring oil, gas and condensate reserves;

Geological substantiation of the system for the development of oil and gas fields;

Geological substantiation of measures to improve the efficiency of development and oil, gas or condensate student.

The tasks of NGPG are in solving various issues related to: with obtaining information about the object of research; with the search for regularities that unite the observed disparate facts about the structure and functioning of the deposits into a single whole; in the creation of processing methods, generalization and analysis of observation and research results; In assessing the effectiveness of these methods in various geological conditions, etc.

This methodological guide offers 11 laboratory work, the execution of which allows you to assign a number of methods for collecting and processing geological and field information, to understand the many key concepts of fishing geology, such as: deposit of oil and gas, the boundaries of the deposits, the heterogeneity of productive strata, conditioning reservoirs, imperfections of wells, reservoir pressure, filtration characteristics of the formation (permeability, hydraulication,

piezoconductivity), indicator diagram, pressure recovery curve (QW), developmental dynamics, oil recovery coefficient.

Laboratory work number 1 Determination of the position of the borders of the oil deposit according to

drilling wells

Detection of an internal structure of the deposit according to measurements, observations and definitions is the task of building a model of the deposit structure. An important stage in solving this task is to carry out geological boundaries. The form and type of deposits depends on the nature of the geological boundaries limiting it.

The geological boundaries include surfaces: structural,

associated with the contact breeds of different age and lithology; stratigraphic disagreement; tectonic disorders; as well as surfaces separating collector breeds (PCs) by the nature of their saturation, i.e. waterproof, gas and gas and gas supplies (IGC, GNA, GVK). Most oil and gas deposits are associated with tectonic structures (folds, raising, domes, etc.), the form of which determines the form of the deposit.

Structural forms, including the form of structural surfaces (roofing and soles of deposits), are examined by structural cards.

The initial data for the construction of a structural card are the layout plan and the magnitude of the absolute marks of the pattern of the surface in each well. The absolute mark is the distance vertically from the sea level to the surface-making surface:

H \u003d (A + AL) -L, (1.1)

where A is an altitude of the mouth of the well, L is the depth of the climbing the surface in the well, D1 - the extension of the well due to curvature.

The method of triangles is a traditional way to build structural cards.

The boundaries of deposits associated with the heterogeneity of the collectors are carried out along the lines along which the permeable PC of the productive reservoir as a result of the facial variability loses collector properties and go into impenetrable, or there was a sequencing or error of the formation. With a small number of wells, the position of the replacement line of collectors, the sealing lines or erosion is carried out conditionally at half the distance between the wells in pairs, in one of which the reservoir is complicated by PCs, and in the other - impermeable rocks or here the reservoir has not been packed or blurred.

The more loyal position of the line of the facial transition of collectors is determined on the maps of changes in the parameters of the formation: porosity,

permeability, amplitude of spontaneous polarization potential

(SP), etc., for which the condition limit is established, i.e. The value of the parameter at which the reservoir loses its collector properties.

The position of the VNC on the deposits is justified by building a special scheme. First of all, we consider wells that carry information on the position of the VNK. These are wells located in a waterproof zone in which BNC can be determined according to GIS data. Wells are also used from purely oil and water zones, in which, respectively, the sole and roof of the formation are in close proximity to the BNK.

A columns of selected wells are applied to the scheme indicating the nature of the saturation of the formation (oil, gas or water) according to GIS, perforation intervals and well test results. Based on this information, choose and conduct a line that is most fully responsible for the provisions of the VC.

On the plan (map) the boundaries of the deposits are the contours of oil and gas. There are external and inner contours of oil and gas. The outer circuit is the line of intersection of BNK (GVK, GNA) from the roof of the reservoir, and the inner circuit is the line of intersection of the BCC (GVK, GNA) with the sole of the layer. The outer circuit is found on the structural map on the roof of the formation, and the inner - on the structural map on the sole of the formation. Within the inner contour there is an oil or gas part of the deposits, and between the inner and external circuits - water impact, or water supply.

With horizontal VCK (GNA, GVK), the position of the lines of the oil and gas content contours are found on structural maps near

appropriate isogeps corresponding to the adopted

gypsomic contact position. With the horizontal position of the contact line, the contour line does not cross the isoipses.

If the productive horizon consists of a plurality of layers characterized by intermittent lithologically unbearable

the position of the contours of the nestlessness as a whole for the horizon is determined by combining structural cards on the roof of each formation (these cards are also applied to the boundaries of replacement collectors and the contour of the oil content for this formation).

On a combined map, the boundary of the complex shape, passing in separate areas along the replacement lines of collectors, and on others - along the external contour line within different layers.

The source data for the implementation of the proposed work is: a table with information about altitudes of the wellhead wells, elongations, the depths of the roof of the formation, the thicknesses of the formation, the depth of the BCN; Scheme of the location of wells.

1. Use the absolute marks of the roof and soles of the formation.

2. Calculate the absolute VNK marks in the wells and justify the position of the VNK on the deposits in general.

E.Ostinet on the location of the wells to distribute collectors.

4. Build structural cards on the roof and the sole of the formation and give them analysis.

5. Show the position of the external and internal contours of the oil content on the specified structural cards.

6. Keep the type of oil deposits and justify its position in modern classifications of oil and gas deposits.

EXAMPLE. Determine the boundaries of the deposit on this system location of the wells according to drilling and geophysical studies (Table 1.1), the depths of the BCN.

Table 1.1.

KSKV	Altituda, M.	Updated, m	G Lubina roof, m	Thickness, M.	Abs. Roof marker, m	Abs. Sole mark, m
	125.7	0.4	2115.1		-1989	-1992
	121.5	0.8	2120.3		-1998	-2002
	120.5		2106.9	8.2	-1983.4	-1991.6
	123.5	1.2	2129.7	11.8	-2005	-2016.8
	122.3	0.2	2121.5		-1999	-2002
	121.9	1.6	2110.5	12.6	-1987	-1999.6
	125.5	0.6	2120.1	14.4	-1994	-2008.4
	125.9	0.2	2129.7	15.4	-2003.6	-2019
	124.3	0.8	2124.7		-1999.6	-2016.6
	126.7	1.4	2142.1	18.8	-2014	-2032.8
		0.5		3.5	-1994.5	-1998
	120.2	0.7			-1986.1	-1991.1
		0.5			-1993.5	-1999.5
	121.5	0.6		4.5	-1995.9	-2000.4
		0.7		4.3	-1991.3	-1995.6
		0.8		5.1	-1996.2	-2001.3
		0.9		5.5	-1996.1	-2001.6
		1.5		4.1	-2000.5	-2004.6

The Depth of the BBC of the GIS is defined in three wells: SCM.2 (2120.3m), SCM.7 (2124.4m) and SC.6 (2121.5m).

Task Performance:

According to formula (1.1), the absolute marks of the roof of the formation are determined (the calculation results are shown in Table 1.1). The same formula is applicable to determine the absolute mark of the BNK, which is in all three wells minus 1998m.

If we assume that the surface of the VC is flat and horizontal, then the data on three wells is enough to make the deposit, as the plane is determined by three points.

The absolute marks of the soles of the formation in this case it is easier to determine using the data on the thickness of the formation (the calculation results are shown in Table 1.1). Structural cards on the roof and the sole of the reservoir are built in absolute marks of the specified surfaces (Fig. 1.1 and 1.2).

The anticline-elongated anticline structure is detected on the maps, complicated by two domes. The structure is a trap of hydrocarbons in the presence of other favorable conditions.

The outer contour of the neboles is carried out on the structural map on the roof of the reservoir, and the inner contour of the neboles is on the structural map along the sole of the reservoir on the isoline -1998m.

The contours of the deposits are unlocked. In the part of the part of the deposit, it can be described as a reservoir consignment, as it is confined to the arch part of the structure, the PCs have a homogeneous structure and a small thickness.

The oil zone is limited by the internal contour of the neboles, and the water jam is limited by the internal and external oil-bearing contours.

Laboratory work number 2 Definition of macro-generic productive horizon

The purpose of this work is to familiarize with the concept of geological heterogeneity on the example of macro-generic, which is taken into account when allocating operational objects and choosing a development system. The development of methods for studying geological heterogeneity and accounting for its estimates and the development of deposits is the most important task of commercial geology.

Under geological heterogeneity, the variability of the natural characteristics of oil and gas saturated rocks within the deposit is understood. R Eheological heterogeneity has a huge impact on the choice of development systems and on the efficiency of oil extraction from the subsoil, to the degree of income of the deposit in the drainage process.

There are two main types of geological heterogeneity: macro-genericity and micronegeneity.

Macro cannonity reflects the morphology of the number-collector breeds in the volume of deposits, i.e. characterizes the distribution of collectors and neollectors in it.

For the study of macro-generation, GIS materials are used for all drilled wells. A reliable assessment of macro components can only be obtained if there is a qualified performed detailed correlation of the productive parts of the wells of wells.

Macro components are studied by vertical (over the thickness of the horizon) and on the strike of the reservoirs (by area).

In the thickness of the macro-genericity manifests itself in the dismemberment of the productive horizon on separate layers and interference.

According to the strike, the macro-generic is manifested in variability of the thickness of the collector breeds up to zero, i.e. The presence of zones of lack of collectors (lithological substitution or seduction). At the same time, the nature of the collector distribution zones is important.

Macro component is displayed by graphic constructions and quantitative indicators.

Graphically macro-generic vertical (over the thickness of the object) is displayed using geological profiles (Fig. 2.1.) And detailed correlation schemes. By area, it is displayed using the collectors of each formation collectors (Fig. 2.2.), On which the boundaries of the spreadsheet of the collector and the neollector are shown, as well as the plots of confluence of neighboring layers.

Fig.2.2. Fragment of the distribution of breed-collector breeds of one of the horizon reservoirs: 1 - rows of wells (H - injection; D - mining), 2 - borders of the distribution of breed-collectors, 3 - boundaries of the fusion zones, sections 4 - distribution of breed collectors, 5 - absence Collector breeds, 6 - fusion of the formation with the overlying layer, 7 - the fusion of the layer with the underlying layer.

The following quantitative indicators characterizing macrosegeneousness are exist:

1. The dismemberment coefficient showing the average number of reservoirs

(interlayers) of collectors within the deposits, cr \u003d (x sh) / n (2.1), where N is

the number of collectors'bears in the i-th well; N is the number of wells.

2. Sand coefficient showing the share of the collector (or the thickness of the formation) in the total volume (thickness) of the productive horizon:

KPESC \u003d [x (KF ^ Bsch)] I / N (2.2), where H ^ is the effective thickness of the formation in

well; N is the number of wells. Sand coefficient is a good carrier of information for the following reasons: It is associated with correlation dependencies with many other geologistic parameters and characteristics of operating facilities: the dismemberment, the intermittentness of the layers in the area, the lithological connection of their context, etc.

As an indicator of macro-generic, taking into account both dismemberment, and sandsyness, a comprehensive indicator is used -

Coefficient of macrogeneity: to m \u003d (X.n I. ) / (Xh I. ) (2.3), where n -

i.=1 i. =1

the number of permeable interlayers; h - the thickness of the open well permeable interlayers. The macro component coefficient characterizes the dismemberment of the development object per unit thickness.

3. The coefficient of lithological connectedness is the fusion coefficient that estimates the degree of merging collectors of two layers, to Sl \u003d S ^ / S ^ where S CT is the total area of \u200b\u200bthe merge sites; SJ. - Square of collector distribution within the deposit. The greater the coefficient of lithological connectedness, the higher the degree of hydrodynamic reporting of adjacent reservoirs.

4. The coefficient of distribution of collectors on the area of \u200b\u200bthe deposit, which characterizes the degree of intermittentness of their location along the area (replacement of collectors with impermeable rocks),

To wait \u003d SA where S is the total area of \u200b\u200bthe zones of the spread of collectors of the reservoir;

5. The complexity of the boundaries of the dissemination of reservoil collectors needed to study and evaluate the complexity of the structure of intermittent, facial formal reservoirs, to Sl \u003d L ^ / N, where - the total length of the boundaries of areas with the distribution of collectors; P is the perimeter of the deposit (length of the external contour of the oil and equipment). It has been established that in inhomogeneous, intermittent layers as the wells mesh seal the complexity is constantly reduced. This indicates that even with a dense grid of mining wells, all the details of the variability of the formation remain unknown.

6. Three coefficients characterizing the zones of collector distribution from the point of view of the conditions of displacement of oil from them:

KSPL \u003d Yasil / Yak; KPL \u003d S ^ S * CL \u003d S ^ S *

where to SPL, CLV, K L -, respectively, the coefficients of continuous distribution of collectors, semilation and lenses; I clocked the area of \u200b\u200bsolid propagation zones, i.e. zones receiving the impact of the displacing agent at least from both sides; S RA - Square Semiily, i.e. zones receiving one-sided effect; - lenses area, not experiencing impact; To spl + to pl + to n \u003d 1.

The study of macrosegeneousity allows you to solve the following tasks when calculating stocks and design design: simulate the form of a complex geological body serving the extensive oil or gas; identify areas of elevated collector thickness arising from the merger of interlayers (reservoirs), and, accordingly, possible places of oil and gas flows between the formation when developing deposits; determine the feasibility of combining the formation into a single operational object; justify the effective location of mining and discharge wells; predict and evaluate the degree of coverage of deposit development; Selecting similar in terms of macro-generic deposits in order to transfer the experience of developing previously developed objects.

The source data when performing a task is a table with data on the thicknesses of the horizon and the breed-collectors, of which it is complicated, the location of the wells, information about the deposits (depth of the location of the deposits, the lithological type of collector, the permeability of collectors, the viscosity of the oil, the deposit mode, the deposits of the deposit) .

1. Build cards isopachitis for each reservoir and horizon as a whole, indicate them the boundaries of collector distribution and give them analysis.

Since the coefficients characterizing the horizon macrogeneity.

EXAMPLE. Determine the coefficients of sandyness, dismemberment, macronegeneousness by multifaceted horizon.

Data in Table 2.1.

Table 2.1 KSKV Places PC thickness Horizon thickness A1 / A2 / A3 0/0/19 A1 / A2 / A3 0/0/7 A1 / A2 / A3 0/4/16 A1 / A2 / A3 0/3/15 A1 / A2 / A3 0/0/20 A1 / A2 / A3 1/5/17 A1 / A2 / A3 2/6/11 A1 / A2 / A3 0/3/15 A1 / A2 / A3 5/16/5 A1 / A2 / A3 5/11/20 A1 / A2 / A3 4/3/10 A1 / A2 / A3 5/4/14 A1 / A2 / A3 2/3/14 A1 / A2 / A3 0/312

Estimated data are presented in Table 2.2

Table 2.2. KSKV Number of interlayers NEF horizon Noblish horizon

According to formulas 2.1, 2.2, 2.3, we determine that the coefficient of the dismemberment of the Kyrgyz Republic \u003d 32/14 \u003d 2.29; The sand cover CPESC \u003d 280/362 \u003d 0.773;

the coefficient of macrosegeneousness KM \u003d 32/280 \u003d 0.114.

The joint use of the Kyrgyz Republic, KPESC, the CM allows you to make an idea of \u200b\u200bthe macro component of the cut: the more kr, km and less KPESC, the higher the macro-generic. Comparatively homogeneous include layers (horizons) with KPESC\u003e 0.75 and cr< 2,1. К неоднородным соответственно относятся пласты (горизонты) с Кпесч < 0,75 и Кр > 2.1. According to these criteria, the horizon, considered in the example, can be described as poorly inhomogeneous (KPESC \u003d 0.773, cr \u003d 2.29)

Laboratory work number 3 Definition of conditioned limits of parameters of productive reservoirs

The correct calculation of oil and gas reserves implies the disclosure of the internal structure of the estimated object, the knowledge of which is necessary to organize the effective development of deposits, in particular to select the development system. To identify the internal structure of the deposit, it is still necessary to know the position in terms of boundaries between the collectors and nonollectors conducted by the values \u200b\u200bof the filter-capacitive (or any other) properties of rocks called conditioned.

The conditioned limits of the parameters of productive reservoirs are the boundary values \u200b\u200bof the parameters on which the breeds of the productive reservoir are divided into collectors and neollectors, as well as collectors with different field characteristics in order to more reliable allocation in the total deposit of its effective amount in general and volumes of different productivity, T .. The definition of collectors' conditional means determining the selection criteria in the context of collectors and their classification by lithology, productivity, etc.

Conditions to stocks are a set of requirements for geological, technical and economic and mining parameters of the deposits, ensuring the achievement of model oil recovery in the profitability of the development process in compliance with labor protection, subsoil and environmental legislation. The definition of considerations for reserves is used to assess the commercial features of the deposits and the classification of geological stocks on their industrial significance.

Conditions of collectors are determined by a large group of factors that determine the filtration and capacitive properties of rocks (FES). The main parameters affecting the FES are porosity, permeability, oil, gas, bitumerativity, supplemented by the parameters of carbonicity, clayness, residual water, the nature of oil, gas, bitumenation, particle size distribution, material-agenetic typing, the parameters of geophysical well research (GIS ) - the saturation parameter, porosity parameter, etc., as well as commercial indicators - productivity or specific flow rate. The method of substantiation of the condition is a correlation analysis between the specified properties of rocks according to the laboratory test of the core, according to GIS and hydrodynamic studies.

Conditions on reserves depend on the social needs for hydrocarbon raw materials and on the level of technical and technological development of oil, gas, bitumertic. Conditions on reserves are justified taking into account the specific reserves, the initial and final flow rate, the displacement coefficient, the oil extraction coefficient (KIN), the development system, limiting cost. The method of substantiation of the condition is technical and economic settlements on the development of the object.

Selection of collectors.

The natural tank, containing hydrocarbons, includes at least two classes breed: collectors and neollectors. These classes are characterized by the structure of the pore space, the values \u200b\u200bof petrophysical parameters, the nature of their distribution.

The borders of the classes are the boundaries of the qualitative and quantitative transition from some properties to other, independent of the technologies used by the development of productive reservoirs. However, it should be borne in mind that when using methods of intensive effects on the reservoir, significantly affecting the structure of the pore space (expanding filtering channels, dissolving carbonates in physical and chemical impact, the creation of cracks, etc.), can be transferred to the highest classes, and when applying methods Calmotation - to the lower.

It has already been noted above that the main parameters characterizing the collectors are the porosity of the KP, the permeability of the CRC, the content of the residual water, for the collector, which enlisters the hydrocarbons - oil, gas, bits of the KN (g, b).

The dependencies between geological and field parameters are statistical, complex, including the components characterizing certain classes of rocks or collectors. When processing such dependencies, the least square method is used. Practice showed that these dependencies are approximated by parabola y \u003d a * x b.

The change in the nature of the dependence is controlled by the change in parabola coefficients for different sections of the correlation field, and the points of intersection of parabola indicate the position of the borders of the classes.

To find these boundaries, the correlation field is often built in bilogariform coordinates (method of linearization), where the parabola is converted into direct: LGY \u003d LGA + B * LGX. Point intersection points indicate the borders of the classes.

The argument and function should be chosen according to the physical meaning, for example, in a pair of KP-KB: CP - argument, and KB - function, in a pair of KP-CRC: KP - argument, CRP - function.

As the basis for determining the boundaries of classes, the CRC correlation field is recommended \u003d F (KP).

There are two conditioned limits. The first limit is the limit above which the breed may contain U.V. The second limit is the limit above which the breed is able to give U.V. The first limit is the lower border of the collector, the second limit is the border of the productive manifold. The first limit is established according to the data of lithologic-petrographic studies of the core and petrophysical properties of rocks. The second limit is established according to the results of the study of the characteristics of the displacement on the core samples, according to the crooked permeability curve, depending on the dependence of the residual water from porosity and permeability. The second limit must be confirmed by the results of the testing of wells - comparing permeability with productivity. The dependence of productivity (or specific flow rate) from permeability, taking into account the minimum amount of the flow rate, below which the development is not profitable, allows you to determine the third limit - technological.

GIS are the most massive type of research. According to GIS, the main parameters of the formation and their classification are made.

There are two ways to substantiate condition according to industry geophysics.

"Kuban State Technological University"

Faculty of full-time training of the Institute of Oil, Gas and Energy.

Department of Oil and Gas Protection

LECTURE NOTES

By discipline:

« Geology of oil and gas»

for students of all forms of training specialties:

130501 Design, construction and operation of oil and gas pipelines and oil and gas stations;

130503 Development and operation of petroleum and gas fields;

130504 Drilling of petroleum and gas wells.

bachelors in the direction of 131000 "Oil and Gas Business"

Compiler: Senior Lecturer

Shostak A.V.

Krasnodar 2012.

Lecture 1-Introduction .................................................................................... 3

LECTURE 2- Natural flammable fossils ......................................... ..12

LECTURE 3- Features of the accumulation and transformation of organic compounds during lithogenesis ..................………………….19

LECTURE 4 - The composition and physico-chemical properties of oil and gas ....25

LECTURE 5 - The nature of the change in the composition and physicochemical properties of oil and gas, depending on the influence of various natural factors .............................................................................. .. 45

LECTURE 6 - Problems of origin of oil and gas ............................56

LECTURE 7 - Migration of hydrocarbons ......................................................62

LECTURE 8 - Formation of deposits .......................................................................75

LECTURE 9 - The zonality of oilformation processes ......................81

Lecture 10- Patterns of spatial placement of accumulation of oil and gas in the earth's crust ................................................ 101

Lecture 11 - oil and gas fields and their main classification signs ............................................................ .108

List of references ....................................................................................112

Lecture 1 Introduction

Among the most important types of industrial products, one of the main places occupy oil, gas and their products processing.

Before the beginning of the XVIII century. Oil, mostly, mined from kopankov, which were attached to the shoulder. As oil accumulated, the oil was trapped and exported to consumers in leather bags.

The wells were attached to a wooden lamp, the final diameter of the attached well was usually from 0.6 to 0.9 m with some increase in the book to improve the inflow of oil to its bottomhole part.

The rise of oil from the well was produced using a manual gate (later equestrian drive) and the rope to which Burdyuk was tied (a bucket of leather).

By the 70th of the XIX century. The bulk of oil in Russia and the world is produced from oil wells. So, in 1878, there are 301 in Baku, the flow rate of which is many times greater than the flows of the wells. Oil from wells was mined with a metallic vessel (tube) with a height of up to 6 m, which is mounted in the bottom of the reverse valve, opening at the immersion of the ventilation into the liquid and closing up when it is moved. The rise of the venture (tarting) was carried out by hand, then on horse rod (beginning of the 70s of the XIX century) and with the help of a steam machine (80s).

The first depth pumps were applied to Baku in 1876, and the first depth rod pump - in Grozny in 1895, however, the tartal method remained the main time. For example, in 1913 in Russia, 95% of oil was produced by ocherism.

The purpose of studying the discipline "The geology of oil and gas is" the creation of the base of the concepts and definitions forming the fundamental science - the basics of knowledge about the properties and composition of hydrocarbons, their classification, the origin of hydrocarbons, on the processes of formation and laws of the placement of oil and gas fields.

Geology of oil and gas - Geology industry, which studies the conditions for the formation, placement and migration of oil and gas in the lithosphere. The formation of geology of oil and gas as science occurred at the beginning of the twentieth century. Her founder is Gubkin Ivan Mikhailovich.

Geology

Lecture notes

Types of oil and gas provinces, regions and oil and gas zones.

Provinces

Oil and gas region.

Zone oil and gas support

The concept of "breed collector".

Types of hollow space.

General patterns of distribution of oil and gas clusters in the earth's crust.

Oil and gas generics of the territory.

The concept of "breed-tire" and the classification of fluidoofers in the area of \u200b\u200bdistribution.

Migration, differentiation of hydrocarbon accumulation.

Chemical composition and physical properties of gases.

Chemical composition and physical properties of oil.

Territory collectors.

Salt and sulfate tires.

Types of permeability and methods for its definition.

Primary and secondary porosity.

Inorganic and organic theory of occurrence of oil and gas.

The elements of the deposit (on the example of the plastic archway).

Types of porosity.

Clay and carbonate fluidophores

Change collecting properties with depth.

Classification of breed collectors.

Natural tank. Types of natural tanks

From which factors depend on the collector properties of rocks.

The concept of "trap for oil and gas". Types of traps by origin.

The concept of "deposit" and the location of oil and gas.

Classification of deposits

Migration of oil and gas. Types of migration.

Factors causing hydrocarbon migration.

Destruction of hydrocarbon deposits.

Differential calamization of oil and gas.

Classification of fluidofores in lithological composition.

Stages of conversion of organic matter in hydrocarbons.

Timan-Pechopian province. Characteristics of the main deposits.
^ 1. Types of oil and gas provinces, regions and oil and gas zones.

Provinces- This is a single geological province, combining related oil and gas areas with similar features in geology, including stratigraphic major deposits in the context (oil and gas complexes).

According to the stratigraphic age of productive deposits, oil and gas provinces are divided into the provinces of Paleozoic, Mesozoic and Cenozoic oil and gas.

^ Oil and gas region.

^ Zone oil and gas support

Depending on the genetic type of components of the oil and gas zone traps are divided into structural, lithological, stratigraphic and rhymes.

Oil and gas provinces, areas and oil and gas treatment areas belong to regional, and location - to lAN Caps of oil and gas.
^ 2. The concept of "breed - collector".

collectors. territary carbonate

granular or pore cracked (any rock formations) and kavernovy(only carbonate rocks).

Good collectors are sands, sandstones, cavernous and fascinated limestone and dolomites.
3. Types of hollow space.

Distinguish the following types of voids:

1. 
   Pores between the grains of chip and some carbonate rocks caused by the textural features of these breeds.
2. 
   Pores of dissolution (leaching cavity) are formed as a result of the circulation of groundwater mainly in rocks.
3. 
   Pores and cracks arising under the influence of chemical processes (the dolomitization process is the transformation of limestone to dolomite, accompanied by a decrease in volume).
4. 
   Empties and cracks formed as a result of weathered.

Cracks of tectonic origin
4. General patterns of distribution of clusters of oil and gas in the earth's crust.

1. 
   99.9% of deposits are confined to sedimentary clusters of deposits and location.
2. 
   Grinded in oil and gas zones, the totality of which forms oil and gas areas united in large oil and gas provinces. Studying the conditions of occurrence of oil and gas shows that there may be several types of deposits at the same time.
3. 
   In the placement of clusters of oil and gas there is a zonality (regional and zonal)
   • 
     Vertical zonality. At the top of the cut to a depth of 1.5 km contain mainly gas accumulation (1.5 - 3.5 km), with depth of gas reserves, and oil reserves increase. Further (more than 4 - 5 km) again there is an increase in gaseous reserves of y / in and decreases the content of oil reserves (gas-condensate deposits).

1. 
   Education U / in various phase states in various geochemical zones
2. 
   Increased migration capacity of gas compared with oil
3. 
   The process of converting oil into methane at high depths under the influence of high temperatures

• 
  Horizontal (regional) zonality. Example: All oil seats of the predfabcasis are concentrated in the eastern part of this region, and gas and gas-condensate - in the central and western parts of the Pre-Bukcascia. In Western Siberia: Oil - the central part, gas - framing the region, and, mostly from the north. Main factors:

1. 
   Composition of organic matter
2. 
   TD and geochemical setting
3. 
   Migration and accumulation conditions

5. Oil and gas generics of the territory.

Bakirov has developed a classification for regional oil and gas territories. This classification is based on a tectonic principle: platforms, folded areas, transition areas.

The main element of the zoning is the province.

Provinces- This is a single geological province combining related oil and gas areas with similar features in geology, including the stratigraphic position of the main deposits in the context (oil and gas complexes).

Provinces related to platforms: Volgo-Ural, Timano-Pechora. Caspian, Angaro-Lena, West Siberian.

Provinces related to folded areas: Transcaucasian, Tien Shan Pamir, Far Eastern, West Turkmen.

Provinces related to transient regions: Preparation, Pre-Caucasus, Pre-Ural, Prepophal.

Each province consists of several oil and gas regions.

^ Oil and gas region. - Territory dedicated to one of the major geological elements characterized by the generality of the geological history of development, including a number of oil and gas zones.

^ Zone oil and gas support - Association of adjacent, similar to the geological structure of deposits with general conditions of formation.
6. The concept of "breed-tire" and the classification of fluidoofor products along the distribution area.

tires (fluidoopors).

According to the distribution area, the following types of fluidoopors are distinguished:

1. 
   regional - the thickness of practically impermeable breeds common within the oil and gas province or more of it;
2. 
   subregional - the thickness of practically impermeable breeds common within the oil and gas region or more of it;
3. 
   zone - Tasters common within the zone or area of \u200b\u200boil and gas;
4. 
   local - Completed within separate location.

Good fluid foams are clays, salts, plaster, anhydrites and some types of carbonate rocks.
^ 7. Migration, Differentiation Battery U / B.

Migration- It is moving in a sedimentary shell. The migration paths serve pores, cracks, cavities, as well as the surface of the layers, the surface of the discontinuous disorders.

Oil and gas for migration in the free phase are moved to the reservoir and in the first trap meed by them will occur accumulationAnd as a result, the deposit is formed.

If oil and gas is enough to fill the whole range of traps lying on the path of their migration. That first is filled only with gas, the second can be oil and gas, the third is only oil. In this case, the so-called differentiation Oil and gas.
8. Chemical composition and physical properties of gases.

Natural gases are a mixture of various gases. The most common is CH4, N2, CO2.

Classification of natural gases on Sokolov VA:

1. 
   atmospheric gases (The presence of free O2 is a distinctive feature. Main components - N2 (78%), O2 (20-21%), AR (1%), CO2 (0.03%), NE, HE, H).
2. 
   gases of the earth's surface (On the earth's surface, the gas formation processes intensively proceed in conditions of wetlands and in the orst deposits at the bottom of the reservoirs - CH4, H2S, CO2).
3. 
   gaza sedimental thickness (Among the gases of sedimentary thickness, industrial clusters form:
   1. 
      dry (Chem. Composition up to 99% CH4).
   2. 
      backway petroleum (gases dissolved in oils, higher y / in up to 50% (C2H6, C3N8, C4N10 ...), fat (rich) gases).
   3. 
      gaza condensate deposits (ρ \u003d 0.69-0.8 g / cm3 - Very free oil, almost completely throws up to 300 C and does not contain CM-ASF. substances. In the gases of these deposits up to 10% and heavier y / c.
   4. 
      stone gases. deposits (Usually contain a lot of CH4 and is usually enriched with CO2 and N2, heavy y / B, as a rule, are missing in them).
4. 
   gases of erupted rocks

Each of these gases can be in a free, sorbed or dissolved state.

Free gases are contained in the pores of rocks, are found in scattered and in the form of clusters.

The sorbed gas is held on the surface of the rock particles (adsorption), or permeates the entire mass of these particles (absorption).

A group of dissolved gases includes gases of liquid solutions. They are common in aqueous solutions and in oils.

Gas properties:

• 
  density.
• 
  viscosity.
• 
  diffusion- Mutual penetration of one substance to another through the pores when they are coming. The difference in gas concentration in adjacent particles of rocks, as a rule, is directly proportional to pressure and solubility coefficient.
• 
  solubility gases. The solubility coefficient of gases in water depends on the temperature and mineralization of water:
  1. 
     The solubility of y / in gases in oil is 10 times more than in water.
  2. 
     Bold gas dissolves in oil better than dry.
  3. 
     Lighter oil dissolves gas more than heavy.

9. Chemical composition and physical properties of oil.

Dark brown, almost black viscous liquid, fat to the touch, consisting of y / in compounds.

^ Chem. Structure. C-83-87%. N-11-14%. S, N, O is always present in oil, they are 1-3%.

In total, about 500 connections are allocated in oil:

• 
  y / in connection [Alkans (methane, paraffin), cycloalkanes (naphthenovy), arena (aromatic)];
• 
  Heterorganic (all connections. S, N, O).

Nickel, vanadium, sodium, silver, calcium, aluminum, copper, etc. were found in oil ashes.

^ Piz. Properties.

1. 
   Density - Mass substance per unit volume. (g / cm3)

In Russia, they use relative density - the ratio of oil density at 20 c to the water density at 4 s. Most often, the oil density ranges in the range of 0.8-0.92 g / cm3. The oil density depends on the density of the compounds of it forming and on the magnitude of their concentration. (In light oils, light-boiling fractions (gasoline and kerosene) predominate, fuel oil predominate in heavy oils. Oil with a predominance of methane y / in the lighter of oils enriched with aromatic y / c. The larger the content of resin-asphaltene substances, it is harder. In reservoir conditions The oil density is less than on the earth's surface, because oil under the ground contains dissolved gases.)

1. 
   Viscosity - The ability of the liquid to resist while moving its particles relative to each other under the influence of the current forces.

Viscosity determines the scale of migration in the formation of oil deposits. Viscosity plays a big role in the production. Looking in reservoir conditions<, чем вязкость нефти на поверхности. Динамическая вязкость – Пуаз, кинематическая вязкость – сантистокс. Наименьшая вязкость у метановых нефтей, наибольшая – у нафтеновых. Вязкость зависит от температуры: чем больше температура, тем меньше вязкость.

The value, inverse viscosity - fluidity (the larger the temperature, the more fluidity).

1. 
   ^ Surface tension - This is the force with which oil resists changing the smooth surface.
2. 
   Oil has optical activity. The ability to rotate the plane polarization of the light beam.

Oil from more ancient deposits is less optically active than oil from younger sediments.

1. 
   Luminescence - The ability to glow with sunlight.

Oil luminescent differently, depending on the chemical composition: light oil - blue, heavy - yellow, brown, brown.

1. 
   Boiling temperature Oils: lungs are easier than heavy.
2. 
   Frozen temperature Oils: depends on the content of paraffins.

10. Territory collectors.

They are formed as a result of mechanical destruction of previously existing rocks. The most common: sands, sandstones, gravites, coglomatic, breccia, aleurolites. Large debris accumulates near the collapsed rocks, and small ones. The bulk of terrigenous collectors is characterized by interzernone (pore) space - these are inter-rigorous or granular collectors. However, the terrigenous collectors meet collectors with a mixed nature of the hollow space. Cutting-pore and even cavernous pore differences are distinguished.

^ 11. Salt and sulphate tires.

Salt and sulfate rocks include plaster, anhydrite, stone salt. These are breeds of light tones of crystal structure, dense, strong. Formed as a result of loss of salts from shallow reservoirs, communicating with the sea. The best and common hydrochloric coil is a stone salt.
^ 12. Types of permeability and methods for its definition.

Permeability - the ability of the breed to pass through itself liquid or gas in the presence of pressure drop.

For a unit of permeability in 1 Darcy, such permeability is taken in which through the cross section of 1 cm2 with a pressure drop in 1 atm. for 1 sec. It takes 1 cm3 fluid with a viscosity of 1 centipoise. Very often breed, possessing a big porosity. Practically devoid of permeability, such as clay (porosity - 40-50%, permeability - 0).

Types of permeability:

1. 
   absolute (physical) - This is the permeability of the porous medium for gas or a homogeneous liquid in the absence of physico-chemical interactions between the liquid and the porous medium and under the condition of full filling of the pore of the medium with liquid or gas.
2. 
   effective (phase) - This is the permeability of the porous medium for this gas or liquid while simultaneously presented in the pores of another medium.
3. 
   relative- The ratio of effective porosity to absolute.

With constant porosity, permeability may increase with increasing grain size, i.e. Significantly depends on the size of emptiness and grains. Also, permeability depends on the density of laying and the relaxation of grains; on the degree of sorting, from cementation and fracture; From the interconnection of pore, cavity and cracks.

With the same content of the cementing substance in the breed, a sharp drop of permeability is observed in rocks with a large density, poor sorted and dried by grains or debris.

Also, collectors are characterized by different magnitudes of permeability along the simulation and perpendicular to it.

Porosity and permeability can be practically defined:

1. 
   Laboratory, in the presence of samples from wells or from natural deposits
2. 
   on commercial data
3. 
   According to complex data of commercial geophysics

13. Primary and secondary porosity.

Porosity

^ Primary porosity - This is when the pores between the particles of the breed are formed simultaneously with the rock. These include pores between the grains of rocks caused by the textural features of these breeds.

^ Secondary porosity It occurs after the formation of rock as a result of circulation of groundwater, under the influence of chemical processes, as a result of weathelation, as a result of tectonic movements.
^ 14. Inorganic and organic theory of occurrence of oil and gas.

The main positions of inorganic theory

It has a small number of supporters. The main provisions were outlined by Mendeleev.

1. 
   The development of astronomy and the study of the spectrum of cosmic bodies showed in many of these the presence of carbon compounds with hydrogen. For example: in the comet's head gas shell, the presence of CH4, CO, CO2, CN was found. In the planets, the presence of y / c was also detected. In the atmosphere of Jupiter, Saturn, Uranus, Neptune found CH4.
2. 
   In modern volcanic gases there are combustible gases. However, the content of CH4 - 0.004%.
3. 
   Possible synthesis y / in an inorganic way. Proven by the simplest chemical experiments in the XIX B, however, these experiments did not comply with the conditions that could be observed on Earth in any of the stages of its development.
4. 
   The presence of oil or its signs in the erupted or metamorphic rocks. (30 prom. Deposits.)
5. 
   There is a helium method for determining the conventional age of oil and natural gases. Calculations have shown that in most age, oil and gas corresponds to the age of accommodating rocks.

Organic (biogenic) theory

He has a large number of supporters. The main provisions were outlined by Lomonosov. Published by Gubkin in the book "The Doctrine of Oil".

1. 
   99.9% of industrial oil and gas clusters are timed to sedimentary thickness.
2. 
   The focus of the highest resources y / in the deposition of geological periods, which differed by the active life of the biosphere organisms.
3. 
   The structural similarities of a number of organic compounds discovered in precipitation with y / in constituting the bulk of the mass of oil is noted.
4. 
   The similarities of the isotopic compositions of the S and C contained in the oils and organic matter of the accommodating rocks. As part of an organic matter, lindoids, proteins, carbohydrates can be distinguished (after dying the plant and animal world).

Lipoids- Fats, y / in, resins, balms, sterols, waxes, etc. Lipoids in their Him. The composition and molecular structure cost the closer to the compounds, the compounds of oil. Among the lipoids are the main - fats. Conclusion: The absence of any carbonal residues in the oil deposits led the authors of organic theory to the conclusion that fats of animal origin are the main source product for the formation of oil.

Proteins - C, H, N, S, O, P. With anaerobic conditions, proteins are easily destroyed with the formation of fatty and amino acids. Many scientists consider proteins as a starting material for the formation of oil.

Carbohydrates. The detection of chlorophyll oil and its derivatives gives reason to believe in the formation of vegetable material oil.

Gas, oil and water is trapped in accordance with their density. Gas, as the easiest, is located in the roofing part of the natural tank under the tire. Below the volume space is filled with oil. And even lower - water.

Gas cap, oil part of the deposits, gas and water impact contact.
^ 16. Types of porosity.

Porosity - This is the volume of the wet-free space in the breed-collector depends on the textural structural features of the rock.

In collectors consisting of chip rocks, porosity depends on the size, form, sorting of the material area, the laying system of this material, as well as the composition, the number and nature of the distribution of cementing substances.

There are general and open porosity.

• 
  ^ Total (complete or absolute) is the volume of all voids of rocks, including pores, cavities, cracks, associated and unrelated.
• 
  Open - This is the volume of the pores only communicating. Open porosity is less than the total pore volume.

^ Porosity coefficient - This is the ratio of the volume of pores of the rock to the volume of this breed, expressed as a percentage.

Open porosity coefficient - This is the ratio of the volume of communicating pores to the volume of rock. Percent pronounced.
^ 17. clay and carbonate fluid

Clay tires consist of particles of less than 0.01 mm. In addition to the debris material, clay minerals are also present (kaolinitis, montmorillonite, hydroslides, etc.). This is a product of chemical decomposition of magmatic rocks. They are taken out by waters. The porosity coefficient of the clay reaches 50%. . Okodno, clays perform the role of tires, because They are practically impenetrable, because the finest pores in clays are not communicated to each other. There are argillite, pellite and other clay tires.

Carbonate tires were formed as a result of loss of salts from aqueous solutions in shallow reservoirs communicating with the sea. These include limestones of various origin, Dolomites without signs of free space in them. They are often clay, dense, often overlap.
^ 18. Change collecting properties with depth.

With an increase in the depth of the rocks under the influence of geostatic pressure, their density increases, and, consequently, the porosity decreases and increasingly filtering properties deteriorate.

This applies mainly to granular collectors (sands, sandstones, aleurolites).

Improving collector properties with a depth is observed in carbonate and other long-standing fragile breeds subject to cracking under the influence of tectonic and other processes.

In the terrigenous rocks - collectors, secondary porosity at high depths at high temperatures occurs as a result of leaching and dissolving carbonate or carbonate-clay cement under the influence of aggressive hot water saturated with carbon dioxide.
^ 19. Classification of collector breeds.

Mountain breeds with the ability to accommodate oil, gas and water and give them when developing are called collectors.The absolute majority of collector breeds have sedimentary origins. Oil and gas collectors are like territary(sands, aleuritis, sandstones, aleurolites and some clay breeds) and carbonate(limestone, chalk, dolomites) breed.

All collectors by the nature of voids are divided into three types: granular or pore (only chip rocks), trechen (any rock formations) and kavernovy(only carbonate rocks).

There are 3 large groups of collectors: uniformly replicable, uneven replicable, fractured.

5 classes of collectors largest in the magnitude of open porosity are distinguished:

1. 
   Porosity\u003e 20%
2. 
   Porosity 15-20%
3. 
   Porosity 10-15%
4. 
   Porosity 5-10%
5. 
   Porosity<5%

The first 4 grade (industrial interest) have practical importance.

By the nature and nature of the pore space, collectors are divided into 2 large groups:

1. 
   Collectors with intergranular (intergranular) pores - Sands, sandstones, aleurolites
2. 
   ^ Collectors with anesting pore space - Carbonate rocks (limestone and dolomites), in which fracture or cavernos are developed.

Collectors breed are classified by their prevalence, lithological exist and power. According to these features, allocate:

1. 
   regional collectors. They are developed within the largest area of \u200b\u200bthe regions of generation and accumulation of y / in.
2. 
   zone collectors. Have a smaller distribution area, cover oil and gas zones or part of oil and gas regions.
3. 
   local collectors. Developed within local structures or within a group of several adjacent location.

^ 20. Natural tank. Types of natural tanks .

The natural reservoir is a natural product for oil and gas, within which the circulation of fluids is possible. The form (morphology) of the natural tank is determined by the ratio in the section and in the area of \u200b\u200bbreed-collectors with accommodating in them the weak-rotable rocks.

Three types of natural tanks distinguish:

1. 
   plasty

It is a thickness of collector breeds, significantly common in the area and at the same time low power (up to several meters). Represented by terrge breeds. Well sustained in power and lithologically, top and bottom, are limited to impermeable rocks.

1. 
   massive

It is a powerful thickar of collector breeds (several hundred meters). There are homogeneous (carbonate) and inhomogeneous. A special case of a massive natural tank is reefs that are buried pushing thickness of young sediments, reef buildings.

1. 
   lithologically limited from all sides

These include permeable collector breeds, surrounded by impenetrable rocks from all sides. Example: sand lens among impermeable clays.
^ 21. From which the collector properties of breeds depend on the collector properties.

Mountain breeds with the ability to accommodate oil, gas and water and give them when developing are called collectors.The absolute majority of collector breeds have sedimentary origins. Oil and gas collectors are like territary(sands, aleuritis, sandstones, aleurolites and some clay breeds) and carbonate(limestone, chalk, dolomites) breed.

All collectors by the nature of voids are divided into three types: granular or pore (only chip rocks), cracked (any rock formations) and kavernovy(only carbonate rocks).

From the definition of collector breeds, it follows that they must have a capacity, i.e. Emptiness system - pores, cracks and cavities. However, not all rocks with a capacity are permeable for oil and gas, i.e. collectors. Therefore, when studying the collector properties of rocks, not only their void, but also permeability is determined. The permeability of rocks depends on the transverse (to the direction of movement of fluids) of the size of emptiness in the breed. In addition, the rock should have a high coefficient of oil and gas saturation.

^ Conclusion: The main indicators of collector properties of rocks are porosity, permeability and oil and gas saturation.
22. The concept of "Trap for oil and gas". Types of traps by origin.

Trap- This is part of the natural tank, where the speed of movement of fluids - water, oil, gas - their differentiation occurs, and accumulates of oil and gas occur. Trap - This is an obstacle to the movement of the reservoir fluids. In the structure of the trap, the collector is involved and limiting its impenetrable deposits. There are traps on the reservoirs of the reservoir, in areas of restriction by its tectonic, stratigraphic and lithological screens, in protrusions and lenses.

By origin, the following traps distinguish:

• 
  structural- formed by the bending of the layers or the rupture of their continuity;
• 
  stratigraphic - formed as a result of erosion of collectors' reservoirs during the break in the accumulation of precipitation (in the era of ascending movements) and overlapping them by impermeable rocks (in the era of downward movements). As a rule, the thickness of rocks formed after a break in sedimentation is characterized by simpler structural shapes of the occurrence. The surface separating these strata from the thickness arising from the previously called the surface of stratigraphic disagreement;
• 
  lithological - formed as a result of lithological replacement of porous permeable rocks impenetrable;
• 
  rifogenic - Formed as a result of the ignition of the organisms-rhypsheets (corals, msnok), the accumulation of their skeletal residues in the form of a reef body and the subsequent overlap of impenetrable rocks.

About 80% of deposits in the world are associated with structural class traps, the share of traps of other origin (rhythogenic, stratigraphic and lithological) accounts for a little more than 20%.

Each trap has a different genesis:

1. 
   Tectonic,
2. 
   Sedimentation
3. 
   Denudation.

23. The concept of "deposit" and the location of oil and gas.

Oil and gas deposit It is a natural local industrial accumulation of oil and gas in permeable collectors (traps) of various types. The deposit is formed in the part of the reservoir, which establishes the balance between the forces, forcing the oil and gas in the natural tank, and the forces that impede this movement.

Location - This is a set of deposits dedicated to one or more traps in the depths of the same and the same area size.

There are local (deposits and location) and regional (oil and gas area areas, oil and gas regions and provinces).
^ 24. Classification of deposits .

Railing oil and gas They call the accumulation of mineral resources, which arose under the influence of gravitational forces in a trap of a natural tank. The deposit is formed in the part of the reservoir, which establishes the balance between the forces, forcing the oil and gas in the natural tank, and the forces that impede this movement.

The deposits are divided into:

1. 
   Structural
   1. 
      Group of anticline structures. They are confined to local raising of various types:

• 
  Archprings
• 
  Hanging deposits (located on the wings of folds)
• 
  Tectonically shielded (formed along the discharges and spots)
• 
  Involuntary (formed on the contact of the productive horizon with a salt rod or volcanogenic formations)

1. 
   Group of monoclinal structures. Associated with flexure formations or structural noses, or with discontinuous disorders.
2. 
   Group of synclinal structures. It is formed in practically anhydrous collectors under the action of gravity forces, it is extremely rare.
1. 
   Rifogenic. In the rhyhedogenous array, caverno and fracture is very inhomogeneous, so collector properties can vary even at minor distances and flow rates in various parts of an array of unequal.
2. 
   Lithological.
   1. 
      Lithologically shielded:

• 
  Separations of collectors
• 
  Impact sections of permeable breeds impenetrable

1. 
   Lithologically limited:

• 
  Sand formations Rosel Paleorek
• 
  Lentzoid collectors

1. 
   Stratigraphic. Deposits in collectors cut by erosion and overlapped with impermeable rocks of younger age.

25. Migration of oil and gas. Types of migration.

Migration- It is moving in a sedimentary shell.

The migration paths serve pores, cracks, cavities, as well as the surface of the layers, the surface of the discontinuous disorders. Migration can occur in the same thicker or reservoir (intra-splash, intrasemervoire), and it can be from one formation to another (interplastic, interrecomerous). The first is carried out in the persons and cracks, and the second - on breaking disorders and stratigraphic disagreements. Both, and the other may have side tension (along the layers of layers) - lateral, vertical migration (perpendicular to the formation of the formation).

Depending on the physical condition, y / in vary:

• 
  Molecular(W / in dissolved condition with water)
• 
  Phase(U / B are in a free state)

Even moving happens in the form of vapors capable of transforming into oil and gas with a change in temperature and pressure.

In relation to oil and gas stationaries:

• 
  Primary - The process of transition U / in from rocks in which they formed, in collectors.
• 
  Secondary - Moving U / B by breeds-collectors, on breaking disorders, cracks, etc.

26. Factors causing migration y / c.

1. 
   Pressure statistical and dynamic.

Statistical pressure is the sealing of rocks under the action of overlying rocks.

Dynamic pressure is the action of the tectonic forces, withdrawing rocks from normal occurrence and faming them into the folds.

Under the action of the tectonic breed forces are broken down by discontinuous disorders and the redistribution of pressure occurs, also breaks and cracks serve as the migration, gas and water migration paths. With folding formation, part of the rocks turns out to be raised to a significant height and exposed to erosion (destruction). Erosion, on the one hand, affects the change in pressure in the earth's crust, and on the other hand, it can lead to the destruction of layers containing oil and gas.

1. 
   ^ Gravitational factor .

Under the influence of oil and gas is understood as the movement of oil and gas under the influence of gravity (gravity). If oil and gas fall into the collector, deprived of water (synclinal), then, by virtue of their weight, will strive to occupy reduced sections.

1. 
   ^ Hydraulic factor.

In its movement, water is fond of the smallest drops of oil and gas and so on Moves them. In the process of displacement, the differentiation of substances according to their specific grades occurs. Oil and gas droplets, popling over water, are connected to each other and under favorable conditions can form accumulations of oil and gas.

1. 
   ^ Capillary and molecular phenomena.

Because Water is better than oil wets the rock, the forces of the surface tension between the breed and water will be greater than between the breed and oil. This explains the observed sometimes phenomenon of oil displacement with water from small pores into large.

1. 
   Gas energy.
2. 
   Fluid expansion forces.

27. Destruction of deposits y / c.

The accumulations of oil and gas formed as a result of migration and accumulation of them in traps, subsequently can be partially or completely destroyed under the influence of tectonic, biochemical, chemical and physical processes.

Tectonic movements can lead to the disappearance of the trap due to its inclination or formation of a disjunctive disorder, then oil and gas from it will migrate to another trap or surface. If for a long time, large territories are experiencing ascending movements , that oil and gas-containing rocks can be displayed on the surface and HC will scattered.

Biochemical reactions with bacteria decomposing bacteria and chemical processes (oxidation) can also lead to the destruction of oil and gas clusters. Diffusion processes may result in some cases.
^ 28. Differential calamization of oil and gas.

Oil and gas for migration in the free phase are moved in the reservoir in the direction of the maximum angle of the reservoir. In the first trap, met by migrating gas and oil, their accumulation will occur and the result is a deposit. If oil and gas are enough to fill in a number of traps lying on their migration, the first trap will be filled with gas, the second can be filled with oil and gas, the third is only oil, and all the other, located hypsometrically higher, can be empty (contain water ). In this case, the so-called differential captureoil and Gaza. The theory of differential capture of oil and gas when migrating them through a chain of traps communicating with each other, located one above, was developed by Soviet scientists V.P. Savchenko, S.P. Maksimov Regardless of them, this principle was formulated by the Canadian geologist V. Gasou.

The migration of oil and gas in the free state can be carried out not only inside the reservoir, but also through discontinuous displacements, which also leads to the formation of deposits.

If the reservoir moves oil with dissolved gas dissolved in it, then oil (and gas dissolved in it) will be filled at high depths of the trap. After filling out these traps, oil will migrate up the reservoir. In the area where the reservoir pressure will be lower than the saturation pressure, the gas will be released from oil into the free phase and flow along with oil into the nearest trap. In this trap, oil deposit with a gas cap may be formed, or if the gas is much, it will be filled with gas, and oil will be supplanted with them to the following gypsomometrically higher trap, which will contain gas oil or oil deposit. If oil or gas is not enough to fill all traps, then the most highly located from them will be filled with only water. Thus, the differential capture of oil and gas takes place in the formation of their deposits only in cases where the movement and oil and gas is carried out in the free phase.
^ 29. Classification of fluidoopors for lithological composition.

Overlapping petroleum and gas deposits, impenetrable or poor breeds, are called tires (fluidoopors).

Breed-tires differ in the nature of the spread and length, by power, by lithological characteristics, according to the presence or absence of solidity disorders, homogeneity, density, permeability, mineral composition.

By lithological composition, fluidooporas are divided into:

1. 
   homogeneous(clay, carbonate, halogen) - consist of rocks of one lithological composition.
2. 
   heterogeneous:
   • 
     mixed (Sand-clay, clay-carbonate, terrigenous halogen, etc.) - consist of rocks of various lithological composition that do not have clearly pronounced laminations.
   • 
     sustained - consist of alternating the abundances of various lithological differences of rocks.

^ 30. Stages of conversion of organic matter in y / c.

A modern idea of \u200b\u200bthe biogenic theory of occurrence of oil and gas is reduced to the following stages of the conversion of organic matter in y / in:

1. 
   accumulation of organic matter

U / in the organic substance accumulating in precipitation in diffusion-scattered state and the organic matter itself, the mainly of the biochemical processes and microorganisms. Water medium with anaerobic setting. The breed seal occurs. Downlink tectonic movements (bending).

1. 
   generation

As the precipitation and the ever-growing flow of the Earth is immersed, the process of generating y / in is activated, and they emigrate from oil-producing strata to collectors. U / B are in the scattered state. The biochemical setting is preserved without oxygen, tectonic movements.

1. 
   migration y / in

Under the influence of various internal and external sources of energy (tectonic, increased thermal stream, gravitational forces, pressure, capillary forces, leading to ousting y / in water from small pores in large) y / in free or dissolved state migrate to collectors or cracks .

1. 
   accumulation

Migrating, y / in fill traps and form deposits. Presence of collector breeds. Anaerobic medium. The presence of breed-tires (accumulation).

1. 
   conservation y / in

Depending on the nature of further tectonic movements and other geological processes, these deposits are either preserved (5) or collapsed (6). U / B are in the form of clusters. Presence of collector breeds. Saving closures of traps or preserving a favorable slope of the layers. Favorable TD Factors (high temperatures and pressure).

1. 
   destruction (redistribution)

U / B can scatter in a liter or atmosphere. Entering clusters y / in in the aeration zone. Disclosure of traps. Tectonic breed impaired. Filtering U / in traps on tectonic disorders. W / in moving water. Dissolution. Oxidation and decomposition of y / c. U / B are in a dilent condition or in the form of new clusters. Ascending tectonic movements. Movement of reservoir or cracking waters.
^ 31. Timan-Pechopian province. Characteristics of the main deposits.

Located on the C-in European part of Russia. Province area - 350 thousand km2. From the East and C-B borders with the Ural and Pihyme, from the West - the Timan ridge, from the north - the Barents Sea.

Tectonic attitude: Russian platform (is the northeast outskirts), in Pechora Sainishlysis, Paleozoic and Mesozoic sedimentation (7-8 km).

The main industrial importance is the middle-water sandy collectors, which with the overlying Verkhnevonian rocks form a single terrigenous oil and gas complex, productive throughout the entire territory.

A coastal-Nizhne-Perm oil and gas complex, folded by carbonate rocks: the collectors serve fractured and cavernous limestones, productive throughout.

Vuktyl, Yegegie, Usinsky. Voyagozhsky, Shapkin, West-Tebuk, Nibel, Turchaninovskoye, Wanish, Hargynskoye deposits.

^ Usinsky oil field associated with a large anticline fold. Devon: 33 * 12 km, amplitude - 500 m. 2 Oil deposits:

1. 
   In the middle-water terrigenous reservoirs at a depth of 2900-3100 m, the main lithological and stratigraphic lithuage of light oil is open.
2. 
   Middle carbon, carbonate thickness (1100-1400 m 0, massive consolidated seal of heavy oil (height 300 m).

^ Yegegie oil field located at the highest flexible level in our province.

The main industrial facility is the Middle Devon Plast with a total capacity of about 30 m.

Sandstones with lenses and assesses of alaverite and argillite. Heavy oil - 0.95 g / cm3.

^ Vuktyl gas condensate field. Large anticline fold, in the geological structure of Ordor, Selur, coal, Perm, Devonsky, Triassic. Amplitude for Nizhne-Perm sediments - 1500 m. 2 gas condensate deposits:

1. 
   The main one is timed to the powerful carbonate massive thicker of the Perm-coal age. Power 800 m.
2. 
   In sandstones, the ninecalented thicker. Refers to the reservoir consignment. Manifiers serve clays.

Oil origin

In the development of views on the origin of oil 4 stages are distinguished:

1) Double Target;

2) a period of scientific guessing;

3) the period of formation of scientific hypotheses;

4) Modern period.

Bright docking representations are the views of Polish Naturalist XVIII century. Kanonik K. Svka. He believed that oil was formed in paradise, and is the residue of a fertile soil, on which the paradise gardens bloomed.

An example of the views of the period of scientific guesses is expressed by M.V. Lomonosov's idea that oil was formed from coal under the influence of high temperatures.

With the beginning of the development of the oil industry, the issue of the origin of oil acquired an important applied value. This gave a powerful impetus to the emergence of various scientific hypotheses.

Among the numerous hypotheses of the origin of the oil are the most important: organic and inorganic.

For the first time hypothesis organic expressed in 1759 the Grand Russian scientist M.V. Lomonosov. In the future, the hypothesis was developed by Academician IM Gubkin. The scientist believed that the initial material for the formation of oil is the organic substance of marine ils, consisting of plant and animal organisms. The old layers are quickly overlapped with younger, which protects the organicity from oxidation. The initial decomposition of plant and animal residues occurs without access of oxygen under the action of anaerobic bacteria. Next, the reservoir formed at the seabed is descended as a result of the overall bending of the earth's crust characteristic of marine pools. As sedimentary rocks are immersed, the pressure and temperature increases in them. This leads to the transformation of scattered organic matter into diffusely scattered oil. The most favorable for oil supply of pressure 15 ... 45 MPa and temperatures of 60 ... 150 ° C, which exist at depths of 1.5 ... 6 km. Further, under the action of increasing pressure, oil is displaced into permeable rocks, according to which it migrates to the place of formation of deposits.

Author inorganic hypothesis D.I. Ieteleev is considered. He noted an amazing pattern: Pennsylvania oil deposits (US) and the Caucasus, as a rule, are located near large faults of the earth's crust. Knowing that the average density of the Earth exceeds the density of the earth's crust, he concluded that in the depths of our planet, metals are mainly located. In his opinion, it should be iron. During the global processes in the cracks-faults, disseminating the earth's bark, water penetrates it. Having encountered iron carbides on its path, it comes to the reaction with them, as a result of which iron oxides and hydrocarbons are formed. Then the last on the same faults rose into the upper layers of the earth's crust and form oil fields.

In addition to these two hypothesis deserves attention "Space" hypothesis. She was put forward in 1892 a professor of Moscow State University V.D. Sokolov. In his opinion, hydrocarbons were initially attended by a gas-pepped cloud, from which the Earth was formed. Subsequently, they began to stand out from magma and rise in a gaseous state in cracks into the upper layers of the earth's crust, where they condensed, forming oil fields.

The hypotheses of the modern period refers " magmatic "hypothesis Leningrad geologist-oilman, Professor N.A. Kudryavtseva. In his opinion, at high depths in conditions of very high temperature, carbon and hydrogen form carbon radicals, CH 2 and CH 3. Then, on the deep fault, they rise up, closer to the earth's surface. Due to the temperature decrease, in the upper layers of the Earth, these radicals are connected to each other and with hydrogen, as a result of which various oil hydrocarbons are formed.

N. A. Kudryavtsev and his supporters believe that the breakthrough of oil hydrocarbons closer to the surface occurs in ripples in the mantle and earthly crust. The reality of the existence of such channels is proved to be widely distributed on the land of classical and mud channels, as well as kimberlite explosion tubes. Traces of vertical migration of hydrocarbons from crystalline foundation in the layers of sedimentary rocks were found in all wells drilled at large depths - on the Kola Peninsula, in the Volga-Ural Otellence Province, in Central Sweden, in Illinois (USA). It is usually inclusions and bodies of bitumens, filling cracks in magmatic rocks; Liquid oil was found in two wells.

Until recently, a hypothesis was considered generally recognized organic Oil Origin (This was facilitated by the fact that most of the open oil deposits are timed to sedimentary rocks), according to which "Black Gold" lies at a depth of 1.5 ... 6 km. White spots in the depths of the Earth at these depths almost left. Therefore, the theory of organic origin does not give almost no prospects regarding the intelligence of new large oil fields.

There are, of course, the facts of opening large oil fields are not in sedimentary rocks (for example, the Giant White Tiger field, found on the Vietnam shelf, where oil lies in granites), the explanation of this fact gives hypothesis of inorganic oil origin. In addition, in the depths of our planet there is a sufficient amount of source material for the formation of hydrocarbons. Sources of carbon and hydrogen are water and carbon dioxide. Their content of 1 m 3 of the substance of the upper mantle of the Earth is 180 and 15 kg, respectively. The chemical environment favorable for the reaction is ensured by the presence of metal acid compounds, the content of which in volcanic rocks reaches 20%. The formation of oil will continue until water, carbon dioxide and reducing agents are in the depths of the Earth (mainly ironing). In addition, on the hypothesis of inorganic oil origin, it works, for example, the practice of developing a Romaskinsky field (in Tatarstan). It was open 60 years ago and was considered to be worked out at 80% .. According to the State Council under the President of Tatarstan R. Muslimov, each year oil reserves are replenished by 1.5-2 million tons and on new calculations of oil can be produced until 2200g . Thus, the theory of inorganic origin of oil does not only explain the facts that put in a dead end of the "organicists", but also gives us the hope that the oil reserves on Earth are significantly more explored for today, and most importantly - continue to be replenished.

In general, it can be concluded that the two main theories of the origin of oil sufficiently explain this process, mutually complementing each other. And truth lies somewhere in the middle.

Origin of Gaza

Methane is widespread in nature. It is always part of the layer oil. Many methane is dissolved in reservoir waters at a depth of 1.5 ... 5 km. Gaseous methane forms deposits in porous and fractured sedimentary rocks. In small concentrations, it is present in the waters of rivers, lakes and oceans, in soil air and even in the atmosphere. The main mass of methane is scattered in sedimentary and erupted rocks. Recall also that the presence of methane is recorded on a number of planets of the solar system and in distant space.

The widespread methane in nature suggests that it was formed by various paths.

Today, there are several processes leading to the formation of methane:

Biochemical;

Thermocatalytic;

Radiation-chemical;

Mechanochemical;

Metamorphic;

Cosmogenic.

Biochemical processmethane formation occurs in ilya, soil, sedimentary rocks and hydrosphere. There is more than a dozen bacteria, as a result of the vital activity of which from organic compounds (proteins, fiber, fatty acids) methane is formed. Even oil at high depths under the action of bacteria contained in plastic water, destroyed to methane, nitrogen and carbon dioxide.

Thermocatalytic processmethane formation is the transformation into the gas of organic substance of sedimentary rocks under the influence of elevated temperatures and pressure in the presence of clay minerals playing the role of the catalyst. This process is similar to the formation of oil. Initially, the organic substance accumulating at the bottom of the reservoirs and on land is subjected to biochemical decomposition. Bacteria are destroyed by the simplest compounds. As the organic substance is immersed, the operation of the Earth and the corresponding temperature increases the activity of the bacteria fades and completely stops at a temperature of 100 ° C. However, another mechanism of the destruction of complex organic compounds (residues of living matter) in more simple hydrocarbons and, in particular, in methane, under the influence of increasing temperature and pressure were already included. An important role in this process is played by natural catalysts - aluminosilicates that are part of various, especially clay rocks, as well as trace elements and their compounds.

What is different in this case, the formation of methane from the formation of oil?

First, oil is formed from the organic matter of the sapropel type - seizures and the shelf of oceans formed from phyto and zooplankton enriched with fatty substances. Source for the formation of methane is an organic matter of humus type, consisting of residues of plant organisms. This substance for thermocatalysis forms, mainly methane.

Secondly, the main zone of oil formation corresponds to the temperatures of rocks from 60 to 150 ° C, which are found at a depth of 1.5 ... 6 km. In the main zone of oil formation, along with oil, methane (in relatively small quantities) is formed, as well as its heavier homologs. The powerful zone of intensive gas formation corresponds to the temperatures of 150 ... 200 ° C and more, it is below the main area of \u200b\u200boil formation. In the main zone of gas formation in severe thermal conditions, a deep thermal destruction of not only scattered organic matter, but also hydrocarbons of combustible shale and oil occurs. At the same time, a large amount of methane is formed.

Radiation-chemical process Methane formation occurs when radioactive radiation is exposed to various carbon compounds.

It is observed that black fine-disperse clay precipitations with an increased concentration of organic matter are usually enriched with uranium. This is due to the fact that the accumulation of organic matter in precipitation favors the precipitation of uranium salts. Under the influence of radioactive radiation, the organic substance decomposes with the formation of methane, hydrogen and carbon monoxide. The latter itself disintegrates on carbon and oxygen, after which the carbon is connected to hydrogen, also forming methane.

Mechanochemical processmethane formation consists in the formation of hydrocarbons from organic matter (coal) under the influence of constant and variable mechanical loads. In this case, high voltages are formed on the contacts of mineral breed grains, the energy of which and participates in the conversion of an organic matter.

Metamorphic process Methane formation is associated with coal conversion under the influence of high temperatures in carbon. This process is part of the general process of conversion of substances at temperatures above 500 ° C. In such conditions, clays are converted into crystal slates and granite, limestone-in marble, etc.

Cosmogenic process Methane formation describes the "cosmic" hypothesis of the formation of oil V. D. Sokolov.

What place is each of these processes in general, the process of formation of methane? It is believed that the bulk of methane of most gas fields of the world has thermocatalytic origin. It is formed at a depth of 1 to 10 km. A large proportion of methane has a biochemical origin. Its main amount is formed at depths of up to 1 ... 2 km.

The inner structure of the Earth

To date, general ideas about the structure of the Earth have been formed, since the deepest wells on Earth opened only the earthly bark. In more detail about ultra-rotary drilling will be told in the section dedicated to drilling wells.

Three shells are distinguished in the solid body of the Earth: the central - the core, intermediate - mantle and the outer-terrestrial bark. The distribution of the internal geophage on the depths is presented in Table 16.

Table 16 Internal Earth Geographers

Currently, there are a variety of ideas about the inner structure and composition of the Earth (V.Goldshmidt, G. Vashlington, A.E.Fersman, etc.). The Gutenberg-Bulllen model is recognized as the most advanced model of the structure of the Earth.

Core – this is the most dense sheath of the Earth. According to modern data, the inner core is distinguished (which is considered to be in a solid state) and the external kernel (which is considered to be in liquid state). It is believed that the kernel is mainly made of iron with an admixture of oxygen, sulfur, carbon and hydrogen, and the inner kernel has an iron-nickel composition, which fully meets the composition of a number of meteorites.

Next is located mantle. The mantle is divided into the upper and lower. It is believed that the upper mantle consists of magnesia-ferrous minerals-silicates of the olivine and pyroxen type. The lower mantle is characterized by a homogeneous composition and consists of a substance rich in iron oxides, magnesium. Currently, the mantle is estimated as a source of seismic and volcanic phenomena, population processes, as well as a zone of implementing magmatism.

Above the mantle is located earth's crust. The boundary between the earth's crust and mantia is installed on a sharp change of the velocities of seismic waves, it is named by the Mochorovich section, in honor of the Yugoslav Scientist A. Mormhorovich, who for the first time installed it and oceanic and two intermediate-subcontinental and sub-osanic.

This nature of the planetary relief is associated with a different structure and composition of the earth: bark. Under the mainland, the thickness of the lithosphere reaches 70 km (an average of 35 km), and under the oceans 10-15 km (on average 5-10 km).

The continental bark consists of three layers of sedimentary, granite and basalt. The Ocean Cora has a two-layer structure: under a low-power loose sedimentary layer is basalt, which in turn is replaced by a layer folded with a slant with subordinate ultra-bastes.

The subcontinental bark is dedicated to island arcs and has increased power. The subox bark is located under large ocean depressions, in the intracontinental and outskirts of the seas (Okhotsk, Japanese, Mediterranean, Black, etc.) and, unlike ocean, has significant capacities of the sedimentary layer.

The structure of the earth's crust

The earth bark is the most studied from all the shells. It is composed of rocks. Mountain breeds are mineral compounds of permanent mineralogical and chemical composition, forming independent geological bodies, aligning Earth Craer. Mountain breeds for their origin are divided into three groups: igneous, sedimentary and metamorphic.

Magmatic breeds Formed as a result of frozen and crystallization of magma on the surface of the Earth in the depths of the earth's surface or in its depths. These breeds have mainly crystalline. Animals and plant residues are not contained in them. Typical representatives of magmatic breeds - basalts and granites.

Sedimentary rocks Formed as a result of precipitation of organic and inorganic substances at the bottom of the water basins and the surfaces of the mainland. They are divided into crumpled rocks, as well as breeds of chemical, organic and mixed origin.

Chip breed Formed as a result of depositing small pieces of destroyed rocks. Typical representatives: boulders, pebbles, gravel, sands, sandstones, clay.

Breed of chemical origin Due to the loss of salts from aqueous solutions or as a result of chemical reactions in the earth's crust. Such rocks are gypsum, stone salt, brown ironing, siliceous tuffs.

Breed of organic originare petrified remains of animals and plant organisms. These include limestone, chalk.

Breed of mixed originfolded from materials of debrid, chemical, organic origin. Representatives of these breeds - Mergeli, clay and sandy limestone.

Metamorphic breeds Formed from magmatic and sedimentary rocks under the influence of high temperatures and pressures in the thickness of the earth's crust. These include shale, marble, jasper.

The indigenous breeds of Udmurtia extend from under the soils and quaternary sediments on the banks of rivers and streams, in ravines, as well as in various workings: careers, pitchers, etc. The terrigenous breeds are absolutely dominated. These include such differences as the aurolites, sandstones and significantly less - conglomerates, gravites, clays. Carbonate rocks found rarely include limestone I. Megel. All these breeds, like any others, consist of minerals, i.e. natural chemical compounds. So, limestones consist of calcite - compounds of the composition of CASSO 3. Calcite grains in limestones are very small and distinguishable only under a microscope.

Mergeli and clay, except for calcite, contain in large numbers microscopically small clay minerals. For this reason, after exposure to the Mergel with hydrochloric acid at the point of the reaction, clarified or darker stains are formed - the result of the concentration of clay particles. In limestones and Mergels, sometimes there are nests and veins of crystalline calcite. Sometimes it is possible to see the dubs of calcite - the crystals of the crystals of this mineral, which have surprised one end to rock.

Terminic rocks are divided into debris and clay. Most of the root surface of the republic is complexed by chip rocks. These include already mentioned aleurolites, sandstones, as well as rare grave, conglomerates.

The aurolites consist of chip bins of such minerals as quartz (SiO 2), field spasi (KALSI 3 O 8; Naalsi 3 O 8 ∙ Caal 2 Si 2 O 8), other dust particles with a diameter of no more than 0.05 mm. As a rule, the aleurolites of the weakness of semplaries, lumps and in appearance are reminded by clays. From clay, they differ in large petrol and less plasticity.

Sandstones - the second common indigenous breed of Udmurtia. They consist of chip particles (grains) of various compositions - quartz grains, field spatts, silicon and effusive fragments (basalt) rocks, as a result of which the sandstone data is called polyminamic or polymineral. Summer particles size ranges from 0.05 mm to 1 - 2 mm. As a rule, sandstones are weakly semplarified, easily loosen and therefore used for construction purposes as ordinary (modern river) sands. In loose sandstones, there are often concerns, lenses and concretion of lime sandstones, whose debris material is selected by calcite. In contrast to the aleurolites, sandstones are characteristic of both horizontal and oblique lamination. In the sandstones, the occasionally marked small lime shells of freshwater bivalve mollusks. All combined (oblique layering, rare mollusks) indicate a river, or alluvial, the origin of polymic sandstone. The cementation of sandstone calcite is associated with the collapse of calcium bicarbonate in the groundwater circulated through the pores of the sand. Calcite has been released as an insoluble reaction product as a result of carbon dioxide.

Less often terrigenous rocks are represented by grave and conglomerates. These are strong rocks consisting of increasing (round, oval) or smoothed debris of brown mergels, sampled by calcite. Mergeli - local origin. In the form of impurities in the chip material, dark silica and effusive (ancient basalts) entered by Perm rivers from the Urals. The size of chips of gravites ranges from 1 (2) mm to 10 mm, respectively, in conglomerates from 10 mm to 100 mm and more.

Basically, oil field is timed to sedimentary rocks, although there are fields of oil dedicated either to metamorphic (Morocco, Venezuela, USA), or to magmatic rocks (Vietnam, Kazakhstan).

13. Plastic collectors. Porosity and permeability.

Collectorit is called a rock, possessing such geological and physical properties that ensure the physical mobility of oil or gas in its void space. The manifold breed can be rich both in oil or gas and water.

Breeds with such geological and physical properties in which the movement of oil or gas is physically impossible in them, called nonollectors.