RU2547847C1 - Method for development of shale oil and gas bearing deposits and process system of equipment for its application - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: according to the method capital mining operations are carried out on penetration and developing access channels to a productive formation of a deposit. Underground mining and development operations and field operations on the well production of shale oil and gas are performed using multistaged hydraulic fracturing or thermal effect on the formation. A shale oil- and gas-containing deposit is penetrated by vertical shafts. Preparation of the productive formation for hydrocarbon production is carried out by the underground mining and development openings placed below a water-bearing horizon covering the rock above the shale rock of the deposit. Hydrocarbon production is carried out by mining blocks of underground producing wells with horizontal sections protruded in the formation. The producing wells are drilled from underground cells constructed mainly in the mining and development openings. Before complete hydraulic fracturing of the formation small diagnostic hydraulic fracturing of the formation is made in the producing wells of a small diameter, which are drilled mainly from the mining and development openings to the whole thickness of the productive formation transversely to its course. The product of the producing wells is divided in the shaft bottom into shale gas and shale oil. The shale oil is outputted to the surface for further treatment before delivery to consumers. The shale gas is burnt in the boiler of a shaft bottom heat-generating plant to generate water steam or hot water used for the production of electricity or for the purpose of a thermal effect on the productive formation in order to increase intensity and the production rate.

EFFECT: reduced total volume of operations on drilling producing wells while developing shale deposits.

2 cl, 11 dwg

Description

The proposed inventions relate to the fuel and energy complex and can be used in the development of unconventional sources, primarily shale oil and gas deposits (streams), for oil production and electric energy production.

Known underground energy technology complexes for the development of solid fuel deposits and the production of electric energy [1-3]. Well-known technologies for oil and gas production, which form the basis of the entire oil and gas industry of the world energy [4-7] and provide mankind for many decades in hydrocarbon raw materials from the so-called traditional deposits and reserves. However, the limited nature of these reserves, the high degree of depletion of many traditional fields, the constant increase in the costs of extracting and transporting oil and gas associated with the promotion of oil and gas production in all separated and inaccessible places, including the Arctic conditions of the seas of the Arctic Ocean, necessitate the search and development of new sources and hydrocarbon resources.

A new non-traditional resource for hydrocarbon production is shale oil and gas deposits (plei). The Bazhenov Formation is a unique oil and gas object with high reservoir heterogeneities and a mosaic character of low reservoir properties, reservoir isolation, high hydrophobicity and other geological features.

Deposits of the Bazhenov Formation are common in the central part of the West Siberian oil and gas basin. On average, they occur at depths of 1500-3000 m, the thickness of the Bazhenov deposits in the normal section is 25-30 m, and in some cases (anomalous section) reaches 90-100 m. The thickness of the deposits of the Bazhenov formation containing hydrocarbons ranges from 10-12 up to 35-40 m, reaching 60 m in some areas.

Currently, as a result of studies by numerous authors, the following features of the rocks of the Bazhenov Formation have been identified: a relatively small thickness with a distribution area exceeding 1 million km ² ; thin-plate, puff and sheet structure; abnormally high values of apparent resistance in excess of 500 ohm-m (often reaching 1000 ohm-m); high and abnormally high values of natural gamma activity; abnormally reduced rock density; reduced speed of passage of elastic seismic waves through the thickness of the Bazhenov mudstones; abnormally high reservoir pressure in the deposits; confinement of wells with the most significant oil production rates to zones of elevated temperatures reaching 135 ° C; low porosity and permeability of reservoirs of the Bazhenov formation; the presence of vertical and horizontal cracks. The low reservoir properties, especially the low permeability of the enclosing rocks, are the main obstacle to the industrial development of the oil and gas potential of the Bazhenov Formation, which is one of the largest shale deposits in the world, characterized by high oil and gas potential. According to optimistic estimates, the deposits of the Bazhenov formation with an area of about 1 million square kilometers in Western Siberia contain several tens of billions tons of high-quality light oil with a large amount of associated shale gas. The development of shale oil reserves in the Bazhenov Formation will prevent the already begun decline in oil production in the traditional oil and gas fields of Western Siberia and may become a real alternative to the very expensive and far from indisputable development of hard-to-reach oil and gas fields in the Arctic and Eastern Siberia.

The currently existing downhole technology for prospecting, exploration and development of traditional oil and gas deposits (deposits) is largely chaotic in nature with a significant degree of randomness and a rather low, in addition, oil recovery ratio. Therefore, the development of deep-seated shale oil and gas deposits, especially such as deposits of the Bazhenov Formation of Western Siberia, requires fundamentally new approaches that would, on the one hand, minimize elements of uncertainty in mining operations, and, on the other hand, maximize the recovery factor oil and gas and thereby led to a significant increase in the economic efficiency of oil and gas production in general [8, 9]. In fact, we are talking about the need to switch to the technology of continuous “excavation” or, as it were, “stripping” of shale deposits in a sense, similar to how this has been done during the last few centuries during underground mining of reservoir deposits of solid fuel - coal.

The closest to the proposed inventions are the borehole method of developing shale oil and gas deposits and a set of equipment based on drilling oil and gas wells with long horizontal sections along the formation, subsequent multistage hydraulic fracturing and various, primarily physicochemical, effects on the underground (productive) formation to increase the intensity and magnitude of oil recovery [10] (prototype). However, the existing method and complex of equipment for the development of shale oil deposits have several drawbacks, which is why economic efficiency and profitability of shale oil and gas production are possible only at sufficiently high prices for oil and gas extracted from traditional oil and gas fields and deposits. From an environmental point of view, the existing method and complex of equipment for the production of shale oil and gas are not at all permissible in a number of practically extremely important situations, for example, in densely populated places and regions of the world. Oil and gas wells in shale deposits, as a rule, quickly decrease their output (flow rate), and therefore the required volumes and drilling speed sharply increase, which with an increase in the depth of productive formations lead to an unacceptable increase in the cost of hydrocarbon production. According to reports, the cost of oil and gas wells for the production of shale oil and gas is 3-4 times higher than the cost of wells in traditional fields and ranges from 3.0 to 15 million US dollars. At the same time, the number of wells that need to be drilled in shale deposits is ten times (sometimes up to 100 times) greater than the number of wells in conventional production.

In addition, the implementation of hydraulic fracturing requires a very large amount of water and the so-called proppant component-proppant (for example, in the form of river sand), as well as many aggressive chemicals that stimulate the release and influx of hydrocarbons to wells, maintaining the permeability of the formation after hydraulic fracturing and well operation process. All this creates opportunities for the uncontrolled and dangerous spread of harmful substances into aquifers and water bodies used as sources of water supply, which is unacceptable in densely populated areas of many countries, and can also contribute to the initiation of sufficiently strong seismic phenomena - earthquakes. In addition, shale gas, which is usually associated with the production of shale oil, has a relatively low (approximately two times lower than that of natural gas) calorific value. Because of this, the utilization, collection and transportation of shale gas produced together with shale oil over long distances is disadvantageous and therefore it is flared in significant quantities in flares. When carrying out multi-stage hydraulic fracturing of a productive formation (shale deposit) located at a considerable depth from the day surface, from where the hydraulic fracturing medium is injected under high pressure, significant volumes of this hydraulic fracturing medium (for example, water), as well as expensive and aggressive chemical additives, are required on the reservoir, which circulate between the day surface and the reservoir during multistage hydraulic fracturing. All this also leads to a high cost of multistage hydraulic fracturing and physical and chemical stimulation of the formation, necessary to increase the intensity and magnitude of oil and gas recovery of the formation and production (production) wells, and is also associated with an increased risk of significant leakage of these substances into the environment (atmosphere , surface and subsoil waters, aquifers, etc.). Among the significant drawbacks of the known method of shale oil production by wells that are drilled directly from the surface above the shale reservoir, in particular from deep-seated productive formations, there is also a high uncertainty regarding the results of multistage hydraulic fracturing and intensifying physicochemical effects on the formation and production wells from for a wide variety of reservoir properties and permeability characteristics of reservoirs in shale deposits. The creation in such conditions of an effective, sufficiently stable and long-running drainage system and hydraulic fracturing geometry is quite problematic and very expensive, and the development of standard and generally applicable schemes and techniques for solving this problem, which can be said to be central to the production of shale oil, is hardly possible at all .

The aim of the proposed invention is to increase the economic efficiency and environmental friendliness of the production and use of hydrocarbons in the development of shale oil and gas deposits.

The technical result of the proposed inventions is to reduce the total amount of work on drilling production wells during the development and operation of deep-seated oil and gas shale deposits, the possibility of volumetric formation of a fracture system for hydraulic fracturing of a productive formation in a drainage system of excavation blocks of underground production wells and to increase the environmental cleanliness of all technological processes for the production and use of shale oil and gas.

This goal is achieved by the fact that in the method of developing shale oil and gas deposits, including capital mining to open and create access channels to the productive formation of the reservoir, underground mining and operational work on the borehole production of shale oil and gas using multi-stage hydraulic fracturing or thermal exposure to the formation , the opening of shale oil and gas deposits is carried out by vertical shaft shafts, the preparation of the reservoir for coal mining Hydrogens are carried out by underground mining preparatory workings located below the aquifers of the covering rocks above the shale rocks of the deposit, hydrocarbon production is carried out by extraction blocks of underground production wells with horizontal sections extended in the formation, production wells are drilled from underground chambers constructed in the main mining workings, before complete hydraulic fracturing in production wells carry out small diagnostic hydraulic fracturing in small wells meters drilled from the main mining workings to the full capacity of the productive formation across its strike, the production of production wells in a near-barrel yard is divided into shale gas and shale oil, shale oil is supplied to the surface for further preparation for shipment to consumers, and shale gas is burned in a boiler near-barrel heat-generating installation for the production of water vapor or hot water used to generate electrical energy or heat exposure of the reservoir I increase the intensity and magnitude of oil recovery.

This goal is also achieved by the fact that the technological complex of equipment that implements the proposed method and includes vertical mine shafts, underground mining workings, equipment for drilling underground production wells with horizontal sections, passed through the reservoir, and their operation using multi-stage hydraulic fracturing or thermal impact on the reservoir, as well as technical means of cleaning and separating shale oil, is equipped with a steam power plant with ground with a steam-generating compartment and a steam-turbine compartment located on the day surface, which are interconnected by a thermally insulated steam pipeline and a spillway with an underground electrohydrogen generator, as well as an underground cleaning and separation unit for production of production wells, the oil output of which is connected to the input by a trunk pipeline surface installation for the preparation of shale oil, and the gas outlet of an underground installation for the purification and separation of products and wells are fed to the boiler inlet of the steam generating compartment, shale gas combustion products in the boiler are discharged to the surface treatment filters and emitted into the atmosphere through the barrel flue gas pipeline, wellhead equipment for production wells is connected to an underground installation for cleaning and separation of well products, and also to underground storage pools the return flow of the hydraulic fluid of the hydraulic fracturing, and the circuit of the thermal effect on the reservoir is made in the form of at least one pair heating and diverting wells, the vertical sections of which are traversed along the lateral boundaries of the extraction block of the production wells, and their horizontal sections are located directly in the formation as close as possible to each other with the possibility of creating a hydraulic connection between them, moreover, as a heat-generating installation, the thermal action circuit on the reservoir is used boiler of a steam generating branch of a power plant of a technological complex or an autonomous heat generator installed in a separate chamber e main preparatory development.

The proposed method and technological complex for the development of shale oil and gas deposits are depicted and illustrated by the illustrations presented in FIG. 1-11.

In FIG. 1 schematically shows the geological sections of Western Siberia with the allocation of the Bazhenov Formation of shale deposits, which is of greatest interest in the implementation of the proposed method and technological complex of equipment for the production of shale oil and gas.

In FIG. Figure 2 presents a characteristic of the distribution area of oil and gas shale deposits of the Bazhenov Formation of rocks in Western Siberia.

In FIG. 3 shows: 1 - shale oil and gas containing deposit (field); 2 - main vertical shaft shaft; 3 - auxiliary (ventilation) shaft shaft; 4 - near-barrel yard; 5, - the main preparatory underground workings; 6 - auxiliary (ventilation) preparatory underground workings; 7, 8 - underground chambers and rigs ("towers"), respectively; 9 - drill string; 10 - underground accumulating workings-chambers (pools) of the reverse fluid flow after fracturing of the reservoir.

In FIG. 4 depicts: 1 - a shale oil and gas containing deposit (field); 5 - the main underground preparatory development; 11 - underground wells of small diameter (hole-holes) for remote volumetric impact on the reservoir of shale deposits.

In FIG. 5 depicts: 1 - shale oil and gas containing deposit (field); 5 - the main underground preparatory development; 12 - sealers underground boreholes; 13 - production (production) well.

In FIG. 6 shows: 1 ₁ , 1 ₂ - mining (mining) blocks of shale deposits; 2 - the main (main) shaft of the technological complex; 4 - mine workings near the barrel; 5 ₁ , 5 ₂ - the main underground preparatory workings; 14 - fountain fittings and wellhead equipment for the operation of production wells; 15 ₁ , 15 ₂ - pipelines for collecting production wells; 16 - underground equipment for separation (degassing) and pre-treatment of shale oil; 17 - shale oil trunk pipeline; 18 - feed gas shale gas pipeline; 19 - underground steam boiler; 20 - feed water pump; 21 - underground storage tank; 22 - stem thermally insulated steam line; 23 - steam turbine surface steam turbine compartment; 24 - an electric generator; 25 - spent steam condenser; 26 - trunk pipeline spillway; 27 - underground hydrogenerator; 28 - stem (outlet) flue gas pipeline; 29 - surface treatment filters; 30 - smoke exhaust; 31 - chimney; 32 - surface equipment (department) for the purification and preparation of shale oil; 33 - drain pipelines of reverse fluid flow after hydraulic fracturing.

In FIG. 7 shows a similar technological scheme for the development of shale deposits and presents exactly the same objects, equipment and devices as in figure 5.

The difference here, as can be seen from a comparison of both of these figures, is only in the drilling pattern of the extraction (production) blocks 1 ₁ and 1 _{2 with} production wells 13 ₁ and 13 ₂ .

In FIG. Figure 8 shows a diagram of the preparation and development of a mining block for a shale deposit by advanced (preliminary) contouring of the block boundaries with production wells, which are then used as injection wells to maintain the required in-situ pressure in the mining column. The necessary explanations are given directly in FIG. 8.

In FIG. 9 is a diagram of the opening and preparation of the mine field steeply falling shale deposits, which respectively shows the same objects, devices and equipment as described above in figures 1-8.

In FIG. 10 depicted: 1 - shale deposit; 5 - the main underground preparatory development; 34 - underground separate chamber of an autonomous heat generator 35; 36 - heat exchanger of the circulating underground circuit of the thermal effect (heating) of the reservoir of the shale deposits in the excavation (production) block; 37 - hot pipeline; 38 - circulation pump; 39 - distribution hot pipeline; 40 - supply heating well; 41 - horizontal (in-situ) section of the supply well; 42 - outlet well of the heating circulation circuit; 43 - in-situ section of the outlet well 42 of the heating circulation circuit; 44 - outlet pipe of the heating circuit; 45 ₁ and 45 ₂ - sealant wellheads of the heating circuit.

In FIG. 11 shows a diagram of a heating circulation circuit for heating a reservoir in a mining block at high power or during a sharp drop in a shale deposit using two or more pairs of supply and discharge wells 40 and 42, respectively.

The proposed method and technological complex of equipment for the development of shale oil and gas deposits are implemented as follows.

Example 1

Let there be a shale oil and gas containing deposit, for example, deposits of the Bazhenov Formation in Western Siberia, which have a pronounced reservoir character and extend for hundreds of kilometers from west to east and from south to north. As can be seen from FIG. 1 and 2 geological sections and characteristics of the distribution area of the Bazhenov Formation (respectively), the depth of the productive formation varies from 1000-1500 to 3000 meters. In this case, the dip angles (occurrence) of the reservoir at individual points of the shale deposit vary over a very wide range and can range from 0 to 90 degrees.

Because of this and due to the above disadvantages of the known (traditional) methods of producing shale oil and gas, the development of a shale oil and gas field (deposit) according to the proposed method is as follows. Using the wide world scientific, engineering and technical experience in the design and operation of underground mining enterprises, the day surface above the shale deposit is divided into mine fields of approximately rectangular shape with sufficiently consistent angles (occurrences) of the productive formation within the designed mine field. Usually these are mine fields of a gentle, inclined, and steeply dipping bed. As can be seen from FIG. 1 and 2, in the Bazhenov suite prevailing from the point of view of the dip angle, in any case along the geological section in the region of Surgut, there are sections (fields) of a shallow and inclined bed, although there are also sections with a steep dip angle in shale deposits. This takes place, for example, in the area of Bolshoi Salym (Fig. 1, 2), where, as you know, pilot work is being carried out to produce shale oil using traditional shale technology.

After selecting the location and the required parameters (dimensions) of the mine field for the development of oil and gas shale deposits (deposits), the field is opened and prepared by vertical shaft shafts and capital underground mine workings, as shown in FIG. 3. At the same time, centrally double (as the most widely used) vertical shaft shafts are constructed above shale deposit 1: 2 and 3 — main, or main, and auxiliary, or ventilation shafts, respectively, as well as a network of capital mining and development workings: 4 - near-barrel yard, 5 - main preparatory underground mine workings and 6 - ventilation (auxiliary) underground mine workings. The depth of the opening horizon and mine preparation of shale reservoir 1 for mining is chosen so that the capital mining workings are located above the reservoir layer of reservoir 1 and are located above the reservoir by several tens or even hundreds of meters, and the mine field of reservoir 1 is divided into several excavation blocks, for example, two extraction blocks, as shown in FIG. 3. Then, underground chambers 7 are built over the excavation blocks in the main preparatory workings 5, in which traditional drilling rigs ("towers") 8 are placed, adapted as necessary for working in underground conditions and equipped with typical drill strings 9. Storage tanks are also built here underground workings-chambers (reservoirs of the return flow of hydraulic fracturing fluid) 10, necessary for the production of shale oil and gas.

From the preparatory mine 5, small-diameter underground wells (bore holes) 11 are drilled at a given interval power for the reservoir productivity 11 for remote volumetric exposure of reservoir 1 to the reservoir (Fig. 4), with which they conduct an advanced study of the reservoir properties of the shale reservoir and use together with multi-stage hydraulic fracturing in horizontal sections of production wells 13 to form an effective volumetric drainage system of a productive formation of a shale reservoir (Fig. 5). After conducting a preliminary study of the reservoir properties of the formation and conducting hydraulic fracturing of small volume in the bore holes 12, the latter are closed by sealants 12. The drilling pattern of the extraction block by oil and gas production wells within the extraction block may vary. It is selected from various engineering and technical and economic considerations, but is determined mainly by the angle of incidence of the reservoir in the developed mine field (mine) of the shale deposit section 1.

In FIG. 6, presents the technological complex of equipment for the development of shale horizontal and hollow-inclined formations with linear-in-line drilling of excavation blocks. As can be seen, the production wells 13 must have a rather complex spatial orientation with vertical, inclined and horizontal components (sections). In some cases, a simpler radial-fan drilling scheme for the extraction blocks, shown in the technological scheme of the complex shown in FIG. 7. Moreover, according to the proposed method, a leading (preliminary) outline of the boundaries of the extraction block by production wells is also possible (Fig. 8), which are then used as injection wells to maintain the required in-situ pressure in the extraction column and to solve some other problems in the process of working out shale deposits.

Along with the drilling of mining blocks of shale deposits in open-pit and underground mining and quarrying mines, as well as on the day surface, a whole range of technological machines and equipment for the production of shale oil and its associated shale gas, as well as their most rational use, are installed and installed, which described below with the example of the circuit already mentioned above and shown in FIG. 6.

In the main preparatory workings 5 ₁ and 5 ₂ above the mouths of production wells 13 ₁ and 13 ₂ , fountain fittings and wellhead equipment for operating production (production) wells are installed, which are connected to underground equipment for separation by pipelines 15 ₁ and 15 ₂ for collecting production of production wells (degassing) and pre-treatment of shale oil 16. To the exits of the latter are connected the oil pipe 17 installed in the main barrel 2, and also through the gas pipe 18 to the steam boiler 19 installed in the borehole, etc. the angular inlet of which is connected through the feed pump 20 to the underground storage tank 21. The output of the steam boiler 19 through the thermally insulated steam pipe 22 is connected to the inlet of the steam turbine 23 with an electric generator 24 and a condenser 25, forming a steam turbine compartment of the power plant, which is placed on the day surface of the complex. The output of the condenser 25 is fed through a stem spillway 26 pipe to an underground electrohydrogen generator (hydrogenerator) 27 installed in a near-barrel yard 4. The surface treatment filters 29 are connected to the flue gas output channel of the steam boiler 19 through the stem (exhaust) flue gas pipe 28, connected through a smoke exhauster 30 with a chimney 31. On the surface of the technological complex also place the installation for the preparation of shale oil 32, which is connected to the stem oil pipeline 17. Finally, the wellhead udovanie 14 production wells 13 associated with drain pipes 33 with accumulation underground workings cameras (pools) 10 for reverse after fracturing fluid influx into the producing formation excavation pillars.

In addition to the distinguishing equipment listed above, the proposed technological complex for the production of shale oil includes all standard technological equipment for underground mining enterprises (ventilation, drainage, handling operations, etc.), which, of course, are not shown in FIG. 6.

After all construction, installation, preparatory and commissioning works, including after drilling the extraction blocks of the shale deposits in accordance with the accepted scheme, complete hydraulic fracturing of the formation through production wells is carried out and they are put into operation. At the same time, in the oil production mode (during the operation phase), one or several extraction blocks can be in operation at different stages of the production cycle, which is determined by considerations common to underground mining enterprises and oil and gas fields, such as production capacity, service life, profitability, etc. In FIG. 6, as previously noted, two mining blocks are shown in the productive reservoir 1 ₁ and 1 ₂ .

Implementation of the proposed method for the development of shale deposits and the work of the technological complex that implements it at the operational stage is as follows. Production wells 13 ₁ and 13 ₂ through wellhead equipment 14 ₁ and 14 _{2 are} fed through pipelines 15 ₁ and 15 ₂ to underground equipment for separation (degassing) and pre-treatment of shale oil (underground oil treatment unit) 16, from where shale oil passed the first stage of preparation (primarily dehydration and gas separation), through a trunk oil pipeline 17 is fed to the day surface for further and final preparation before being sent to consumers. The shale gas taken from the production of production wells from the underground oil treatment unit 16 is supplied by a gas line 18 to a steam boiler 19 located in a near-barrel yard 4. Water is supplied to the steam boiler 19 by a pump 20 from an underground storage tank 21, which generates water vapor as an intermediate working fluid in the steam-power cycle of energy conversion of an electric power installation (station) with steam-generating and steam-turbine compartments spaced along the geodetic height (Fig. 6) through a thermally insulated stem pipe 22 to a steam turbine 23 with an electric generator 24 and a waste water vapor condenser 25. Condensed water vapor (water) is supplied through a stem spillway 26 to an underground hydrogenerator 27 and then to an accumulating (compensating) underground reservoir 20, and the generated electric the energy in the electric generator 24 and the hydrogenerator 27 is used for the own needs of the energy technology complex and for supply to external consumers. The products of shale gas combustion (flue gases) from the steam boiler 19 are delivered to the surface of the complex via the trunk (exhaust) pipe 28 and, after treatment in the treatment filters 29 with a smoke exhaust fan 30, are emitted through the chimney 31 into the atmosphere. At the same time, in a surface installation for the preparation of shale oil 32, final refining and degassing (separation) of oil is carried out, clean oil is supplied to the main means of transport for further use (for processing), and the separated shale gas residues are used for gas supply to local consumers or for subsequent gas chemical processing. In the future, as the mining columns 1 ₁ and 1 _{2 are} worked out (Fig. 6), the next operations are performed of multistage complete hydraulic fracturing of the producing formation carried out through production wells 13 ₁ and 13 ₂ . In this case, the working fluid of the return flow of hydraulic fracturing before entering these wells into the operation mode for oil production is accumulated in the underground workings-chambers (pools) 10 ₁ and 10 ₂ through the drain pipelines of the fluid of the return flow 33 ₁ and 33 ₂ . In underground workings-chambers (pools) 10 ₁ and 10 ₂ during the development of the shale field, certain measures can be taken to detoxify and disinfect the fluid from the return flow of hydraulic fracturing, which will further improve the environmental cleanliness of production in the production of shale oil.

Example 2

Let there be a section of shale deposits with the dimensions of a mine field typical for underground mining enterprises, in which the reservoir has a steeply dipping (45 degrees or more) bedding pattern. As can be seen from FIG. 1 and 2, such mine fields in the Bazhenov formation are also available. Such steeply falling sections of the productive shale formation are located mainly in the middle part of Western Siberia and are located at depths of 2000 meters and more. Although in the western part of Western Siberia it is also possible to clearly identify areas of steep fall at depths of about 1500-2000 meters. The development of steeply falling shale deposits according to the proposed method and technological complex remains generally similar to that described for example 1 for horizontal or gently inclined bedding of a productive formation. However, there are some negative as well as positive factors that should be taken into account when producing shale oil in such conditions. First of all, in this case, the opening and preparation horizon must be at a considerable depth, which significantly increases the cost of opening and preparing the mine field. However, a steep fall (occurrence) of the productive formation and its location (location) in a smaller mine field on the surface creates favorable conditions for reducing the cost of mining and preparatory work and the necessary measures for hydraulic fracturing or other physicochemical effects on the formation and wells in the process oil production, as well as drilling of mining columns with production wells, as illustrated in FIG. 9. In FIG. 9 is a diagram of the opening and preparation of steeply dipping shale deposits. This diagram depicts the same objects and devices and they are indicated by the same positions as in the above-mentioned FIG. 3 in the description of example 1 for the development of horizontal or gently-inclined deposits. The technological complex of equipment that implements the proposed method, in this case, has all the same objects, devices and equipment, which are presented in FIG. 6 or 7. The technological complex for the production of shale oil works in the same way as it was just described in Example 1, and the differences here are as follows. When preparing a productive formation for mining (for excavation), it is required to conduct (sinking) only one main preparatory development 5 and only one auxiliary (ventilation) development 6, which is placed directly above the steeply falling (going down) productive formation 1 (Fig. 9). In addition, the drilling of the extraction columns of the productive formation 1 ₁ and 1 ₂ from the main preparatory mine 5 is carried out by a fairly simple - “flat” scheme of production wells with vertical or inclined sections extending in the plane of the formation from the upper to the lower boundary of the steeply falling deposits within this mine field .

Example 3

Existing (known) shale oil and gas production technologies use not only multi-stage hydraulic fracturing and chemical effects on the formation and production wells, but if necessary, other methods of influencing the shale formation are used, in particular, such as thermal exposure or heating of the shale formation for reducing the viscosity of hydrocarbons and increasing their inflows to production wells. The implementation of this way to increase oil recovery and the intensity of tributaries in the reservoir according to the proposed method and technological equipment is carried out as follows (Fig. 10). In the preparation of the extraction column of the shale deposit 1 in the case of a small thickness (about 10-20 m) of the reservoir in the main preparatory mine 5, a separate underground chamber 34 is built in which an autonomous heat generator (heat generator) 35 is installed, which generates thermal energy to the heat exchanger 36 of the circulating underground the heating circuit of the reservoir of shale deposits in the extraction (mining) block. As an autonomous heat generator 35, for example, a conventional electric heating water-heating or steam boiler or an atomic energy reactor, which is adapted to work under given application conditions, can be used. Thermal energy to the heat exchanger 36 at the operational stage of the complex’s operation (after the start of shale oil and gas production in one of the extraction blocks) can be supplied in the usual way also from the steam boiler 19 of the underground steam generating section of the power plant (power plant) of the complex itself (Fig. 6, 7). From the heat exchanger 36 through the hot pipe 37, the circulation pump 38 through the distribution hot pipe 39 pumps hot water into the supply of the heating well 40. In the horizontal (in-situ) section 41 of the supply well 40, hot water is injected (discharged) into the formation at predetermined intervals along the length of the section. On the opposite side with respect to the injection heating well 40, a discharge well 42 of the heating circulation loop is carried out in the extraction column, which also has an in-situ (horizontal) section 43. The latter is carried out in the very close proximity (as close as possible) from the in-situ section 41 of the supplying heating well 40 In addition, the section 43 of the outlet well 42 is equipped so that in it the receiving channels are located as close as possible to the output channels of the coolant (hot water) in the nearby in-situ section 41 of the supply well 40. Therefore, some time after the supply of the hot coolant to the heating circulation circuit between the in-place sections 41 and 43, conductive channels are formed (washed) that are sufficient for the coolant to enter the outlet pipe 44 of the outlet well 42 and further in the heat exchanger 36 to provide a given mode of circulation of the coolant through the reservoir and its heating. In this case, after the formation is heated to the required level in the extraction column drilled by producing wells in one way or another, they begin to produce shale oil and gas in the manner described above. To prevent leaks and breakthroughs of the coolant from the circulation loop of the wellheads 40 and 42 are equipped with sealants 45 ₁ and 45 ₂ .

With a significant thickness of the productive formation (about 50-60 m) or with a steeply falling shale reservoir, the influx intensification and oil recovery of the productive formation by heating it can be carried out according to the scheme shown in FIG. 11 and containing two or more pairs of supply and outlet wells in the heating circulation circuit. At the same time, in order to ensure uniform thermal effect on the formation within the extraction column, the supplying wells 40 ₁ and 40 ₂ and the outlet 42 ₁ and 42 _{2 of the} circulation heating circuit at the vertical boundaries of the extraction column are placed mutually opposite, and pairwise interconnected in-situ sections of the same wells are located at different heights by power or angle of occurrence of the reservoir. It goes without saying that any other energy source can be used as a source of thermal energy in the circulation heating circuit of the formation, for example, as mentioned above in example 2, an underground steam boiler 19 (Fig. 6, 7). However, such an opportunity, of course, may appear only after the start of shale oil production at this technological complex. Another technological possibility of heating the formation using the lateral wells of the circulation heating circuit of the excavation formation 40 and 42 (Fig. 10) or 40 ₁ , 40 ₂ and 42 ₁ , 42 ₂ (Fig. 11) appears by simultaneously feeding horizontal horizontally adjacent sections of wells 41 and 43 (for example, Fig. 10) of chemicals that interact with the release of thermal energy, one of which is an energy carrier fuel, and the other is an oxidizing agent. In this case, fuel is supplied, for example, through a supply well 40, and air (oxidizing agent) through a discharge well 42 (or vice versa). Warming up the reservoir can also be carried out using electric heating elements placed in horizontal sections 41 and 43 through the side wells 40 and 42, respectively. Moreover, in order to reduce costs, the number of lateral wells and their horizontal (in-situ) sections can be reduced by half.

Example 4

Let it be necessary to work out a section of a shale deposit, which within the entire mine field or part of it has sufficiently low and insufficiently reliable information support for constructing detailed geological and filtration models of the reservoir that are necessary for effective management of the hydrocarbon extraction process. Moreover [8, 9], the use of seismic data (GIS) and even exploratory drilling to build detailed geological and filtration models of a productive formation often leads to erroneous and unreliable results. It is this circumstance that can explain the fact that over several decades of hard work and efforts to produce “shale” oil from the Bazhenov Formation in Western Siberia, cumulative production amounted to a little more than 5 million tons. Over the past 30 years, Surgutneftegas alone has drilled more than 600 wells in the Bazhenov Formation, of which 37% were dry. And this despite the fact that domestic scientists placed the main emphasis in their research on the forecast and search for highly productive zones in shale deposits. The experience of developing the Bazhenov Formation using existing technologies (methods) for oil production revealed a number of features and disadvantages, such as a low oil recovery factor (CIN), which, for example, at the Salym field, according to some data, is only 7%, and the distribution of wells with a high initial production rate (the difference in production rates can be several orders of magnitude, from a few tons per day to several hundred), a significant increase in oil recovery after hydraulic fracturing (Fracturing), a sharp decline well productivity - during the year, the production rate may decrease by an order of magnitude, etc.

The proposed method and complex of equipment allows for efficient management of hydrocarbon recovery by forming an active borehole drainage system of the reservoir in the form of horizontal sections of producing wells 13 (Fig. 5) and the simultaneous use of underground boreholes 11 (Fig. 4) as injection wells into the reservoir of the working agent (for example, water) to increase the completeness and intensity of the movement of hydrocarbons to the bottom of the producing well through a system of vertical and horizontal GOVERNMENTAL cracks created during drilling mining (excavation) block and implementing them fracturing operations such as described above in Examples 1-3.

Example 5

The proposed method and complex of equipment for the production of hydrocarbons from shale deposits can be used (implemented) in addition to the cases described above (Examples 1-4) and in other real situations that occur in the practice of extraction of fossil fuels. Suppose, for example, that there is a shale oil and gas containing reservoir (or some part of it), on the surface of which it is impossible to carry out any work on the construction of production facilities, let alone drilling wells and produce shale hydrocarbons using existing hydraulic fracturing technologies (densely populated places of residence of people, important areas of agricultural activity, etc.). But even if there is already one or another network (set) of underground mining enterprises - mines with various shafts and major mining and preparatory workings for opening and preparing a mine field, within which work has been carried out or even is underway, over the shale deposit mining a particular mineral, for example, solid fuel - coal.

It is precisely this situation that exists today in the well-known Donetsk coal basin (Donbass) in Ukraine, a number of coal mines of which are located above the Yuzovskaya shale deposit and which over the years of operation have developed industrial coal reserves or are already at the final stage of work. Moreover, the depth of many of these mines sometimes reaches 1000 and even more meters, and the productive layer of Yuzovskaya Square, as you know, is at a depth of 2000-3000 meters and more. Moreover, according to the available geological data in the Donbass region on the Yuzovskaya shale area, there are mainly gas fields.

In such a situation, the implementation of the proposed method for the extraction of hydrocarbon raw materials - shale gas from the underlying shale rock mass using existing open-cut mines (mine shafts) and underground capital mining workings, as well as the existing mine infrastructure (power supply, hoisting-and-transport complexes, ventilation, drainage, etc.) actually gives such mines of Donbass a second life, turning them into underground shale gas production complexes, with all the ensuing hence the consequences.

At the same time, the formation of extraction blocks for shale gas production, the construction of production wells, hydraulic fracturing of shale deposits or other types of impacts on the reservoir, ensuring the extraction (production) of shale gas, its purification and preparation for delivery to the day surface via a trunk gas pipeline ( instead of a trunk oil pipeline) according to the proposed method will be carried out in exactly the same way as in the above Examples 1-4. Therefore, coal mines (and the Donbass as a whole) as a result of their certain reconstruction and modernization according to the proposed inventions, can be a large-scale experimental industrial platform - the basis for solving such a unique technical and economic problem as the industrial development of oil production from shale deposits of the Bazhenov Formation of Western Siberia . In conclusion, it is also necessary to indicate that the opening and preparation of productive formations of shale oil and gas deposits for underground mining can be carried out not only using centrally double shaft shafts, as was the case in the description of the above examples of the implementation of the proposed method, but also using a centrally-related opening and ventilation schemes, in which the auxiliary - ventilation - shaft of the mine is located at one of the boundaries of the mine field. Such a solution may turn out to be more preferable when mining sections (mine fields) of shale deposits with abnormally increased in-situ pressures and temperatures, which, as is known, also occurs in the case of rocks of the Bazhenov Formation of Western Siberia.

Used sources

1. Ilyusha A.V. Nuclear power plant. - Copyright certificate No. 1828710 (1989).

2. Ilyusha A.V. Hydroaccumulative power station. - Patent No. 1828711 (1990).

3. Ilyusha A.V. etc. A method of developing coal deposits and a set of equipment for its implementation. - RF patent No. 2027854 (1995).

4. Korshak A.A., Shammazov A.M. Basics of oil and gas business. - Ufa, Ed. "DesignPolygraphService". 2002, 543 p.

5. Oil and gas construction: Textbook. Ed. I.I. Mazur and V.D. Shapiro. - M.: Publishing. OMEGA-L, 2005 .-- 744 p.

6. Tetelmin VV, Yazev V.A. Fundamentals of oil and gas engineering. - M.: Publishing. SAYNS-PRESS, 2009 .-- 344 p.

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Claims (2)

1. A method of developing shale oil and gas deposits, including capital mining to open and create access channels to the productive formation of the reservoir, underground mining and operational work on the borehole production of shale oil and gas using multi-stage hydraulic fracturing or thermal stimulation, characterized in that the opening of shale oil and gas deposits is carried out by vertical shaft shafts, the preparation of the reservoir for hydrocarbon production is carried out underground mining and preparation workings located below the aquifers of the covering rocks above the shale rocks of the deposit, hydrocarbon production is carried out by extraction blocks of underground production wells with horizontal sections extended in the formation, production wells are drilled from underground chambers constructed in the main mining workings before full hydraulic fracturing in production wells carry out small diagnostic hydraulic fracturing in small diameter wells drilled from main mine workings for the entire capacity of the productive formation across its strike, the production of production wells in the near-barrel yard is divided into shale gas and shale oil, shale oil is supplied to the surface for further preparation for shipment to consumers, and shale gas is burned in the boiler of a barrel-shaped heat generating unit for the production of water steam or hot water used to generate electrical energy or heat on the reservoir reservoir to increase the intensity Evidence and magnitude of oil recovery. 2. The technological complex of equipment for the development of shale oil and gas deposits, including vertical mine shafts, underground mine workings, equipment for drilling underground production wells with horizontal sections, passed through the reservoir, and their operation using multi-stage hydraulic fracturing or thermal impact on the reservoir, as well as technical means of cleaning and separating shale oil, characterized in that the complex is equipped with a steam power plant with The ground is located in a near-barrel yard with a steam generating compartment and a steam turbine compartment located on the day surface, which are interconnected by a thermally insulated steam pipeline and a spillway with an underground electrohydrogen generator, as well as an underground cleaning and separation unit for production of production wells, the oil output of which is connected to the input via a trunk surface installation for the preparation of shale oil, and the gas outlet of an underground installation for purification and separation of products wells was fed to the boiler inlet of the steam generating compartment with the removal of shale gas combustion products in the boiler through the flue gas trunk pipe to surface treatment filters and air emissions, wellhead equipment for production wells is connected to an underground installation for cleaning and separation of well products, as well as to underground storage pools the return flow of the working fluid of the hydraulic fracturing, and the circuit of the thermal effect on the reservoir is made in the form of at least one pair of heat water and diverging wells, the vertical sections of which are traversed along the lateral boundaries of the extraction block of production wells, and their horizontal sections are located directly in the formation as close as possible to each other with the possibility of creating a hydraulic connection between them, and used as a heat-generating installation for the heat treatment circuit on the productive formation boiler of the steam generating branch of the power plant of the technological complex or an autonomous heat generator installed in a separate chamber mainly th preparatory development.

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