RU2593614C1 - Method for mining-well extraction scavenger oil and process equipment system therefor - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: group of inventions relates to fuel and energy industry and can be used for production of high-viscosity scavenger oil. According to method after mine opening of oil deposit and preparation of mining-producing well units, system of force-stimulating reservoir recovery wells is formed by drilling at formation from underground mine-preparatory workings. Production wells are drilled from day surface or directly from ore mining and development workings extraction with common or branched horizontal sections of well shaft. From associated oil gas at oil separation methane is extracted, which is used for generation of electric energy at gas-turbine power plant. Propane-butane component of associated petroleum gas is liquefied under underground conditions and used as displacement working agent pumped into formation through force-stimulating wells. Work on scavenger oil production is carried out with supply to productive formation through a system of force-stimulating wells as displacement working medium of liquefied broad fraction of light hydrocarbons. Said fraction is obtained by separation of associated petroleum gas and/or heat action on formation with circulation loop of heat-bearing fluid with tubular heat exchangers installed in force-stimulating wells.

EFFECT: simplified process of operation and structure of underground equipment, increasing reservoir recovery, reduced cost of well drilling.

2 cl, 5 ex, 9 dwg

Description

The inventions relate to the fuel and energy complex and can be used in the development of fields of hard to extract, mainly shale and high viscosity (bitumen) oil, as well as in the late stage of oil exploitation with traditional reservoirs.

Known methods and equipment for the development of hydrocarbon deposits [1-3], including the opening of reservoirs by producing and injection wells, the selection (production) of formation fluids through production wells, degassing (separation) of oil to separate associated gas and its subsequent combustion thermal power plants for generating electric and thermal energy, which reduce the energy intensity of technological production, as well as supply to the reservoir through injection wells Flue gases from heat generating equipment and formed on the basis of their reagents for EOR. The disadvantage of these methods and equipment complexes is that they do not have the capabilities and properties necessary to create highly effective, from the point of view of spatial-geometric parameters and characteristics, drainage well systems, as well as acceptable and highly effective methods of displacing oil from reservoirs and methods of influencing them within the entire oil reservoir or its parts (blocks). These methods cannot be used at all in the development of deposits with low permeability reservoirs, in particular, for the production of so-called shale oil.

Known methods of oil production, including the so-called horizontal wells, based on various methods of waterflooding of oil deposits and water-gas effects on reservoirs [4-8]. The main disadvantages of these methods are as follows. When operating production wells in natural mode, it is impossible to achieve a high estimated oil recovery and production intensity due to a decrease in the current reservoir pressure to the degassing pressure and oil viscosity, which requires periodic shutdown of production wells to increase reservoir pressure. The presence of horizontal sections in the shafts of injection and production wells, although it increases the coverage of the reservoir by the displacing effect of water, leads to an increase in heterogeneity of oil withdrawal from the reservoir as a whole and, ultimately, leads to a decrease in oil recovery and the inability to achieve high values of the oil recovery coefficient. Moreover, the use of water and water-based displacing working agents is ineffective, and sometimes completely unacceptable with clay components in rocks of oil-containing formations, due to their swelling and a significant decrease in filtering and capacitive properties.

A well-known thermal mine method for developing a fractured reservoir of highly viscous oil [9], including opening and preparing a productive formation with mine shafts and mining workings, as well as drilling a gallery in the lower part or below the oil formation, pumping coolant and taking oil through underground half-inclined, steeply inclined and vertical wells, injection of displacing agent after heating the formation to the optimum temperature. The main disadvantage of this thermoshaft method of producing highly viscous oil is that the thermal effect on the reservoir is carried out by pumping the coolant in the form of water vapor directly into the reservoir itself. This leads to large energy losses during steam generation and a large consumption of water as a working coolant agent, as well as increased dilution (water cut) of the produced oil, which also significantly reduces ultimately the completeness of recovery (ORF) of oil from the reservoir.

There is a method of developing deposits of high viscosity and heavy oil with thermal impact [10], including drilling vertical production and observation wells, the rows of which are sequentially parallel to the fracture fracture trajectories in production wells fixed by geophones in observation wells, and pumping equipment for oil extraction into production wells , descent into observation wells of electric heaters on a cable for heating the formation, as well as sequential transfer of producing wells zhin in observation during development of the deposit (the deposit). The main disadvantages of this method are as follows: multi-operation and technological complexity directly in the process of oil production, a large amount of drilling and the absence of other methods of impact on the reservoir, compatible in time and space, significantly increasing the oil recovery coefficient.

A known method of hydraulic fracturing of rocks [11], based on the use of liquefied carbon dioxide as a hydraulic fracturing fluid, injected into a reservoir with subsequent heating to the temperature of the phase transition of CO ₂ to a gaseous state. However, the injection of CO ₂ into the reservoir, although it contributes to the displacement of oil, leads to an increase in the content of the ballast component in the production of production wells with all the ensuing negative consequences. Equally important is the fact that the method itself is not integrated into the technological links of oil production, even within the framework of a single oil well.

Closest to the proposed inventions is a method of mine-well development of shale oil and gas deposits and a technological complex of equipment for its implementation, including opening and preparing a productive formation with mine shafts and major underground mining and development workings, creating access channels to the productive formation, well production of shale oil and gas using multistage hydraulic fracturing by excavation blocks of underground production wells with hydraulic fracturing and (or) those the impact on the formation, which is drilled from the underground chambers of the main mining workings, pre-treatment and separation of shale oil in underground conditions, the use of shale gas for energy supply and increase the efficiency of the underground energy technology complex, as well as the supply of shale oil after final treatment and preparation at daily surface to consumers [12] (prototype).

However, the main drawbacks of the existing method and technological complex (prototype) include the use of a water-based fluid (hydraulic fracturing fluid) during hydraulic fracturing of the reservoir, which must be subjected to decomposition (decomposition) after hydraulic fracturing, pumping it out of the hydraulic fracturing zone and accumulating this liquid (backflow liquid) in special pools before putting a production well into operation (stage) of oil production. Moreover, directly in the process of production (extraction) of shale oil and gas through an artificially created drainage system, the reservoir does not use any methods to intensify (stimulate) the flow of hydrocarbons to the production well, which ultimately reduces the oil and gas recovery of the reservoir (oil recovery coefficient - CIN), and productivity (flow rate) of the producing well. In addition, all associated petroleum gas of separated shale oil, containing, in addition to methane, and other even more valuable light hydrocarbons, such as propane and butane, are burned in a boiler to produce steam from a steam power plant with a relatively low efficiency. Moreover, the main obstacle to the production of hard-to-recover highly viscous bitumen oil, as is known, is its high viscosity, and not the low permeability of the reservoir, as is the case with shale oil, which necessitates the search for and adequate technical and technological solutions for mining bitumen deposits oil.

The aim of the proposed invention is to increase the economic efficiency, environmental friendliness of production and completeness of hydrocarbon extraction both in the development and operation of new fields with almost any characteristics of reservoirs and oil properties, and at the late stage of development of existing oil fields with traditional reservoirs.

The technical result of the proposed inventions is the utmost possible simplification of the operating technology and structure of underground equipment necessary for the functioning of a system of injection-stimulating oil recovery wells in extraction and production well blocks, reducing the cost of drilling production wells to the usual level currently available in oil production practice, when development of new fields, as well as ensuring the practical feasibility of using the existing stock of producing wells and the existing oilfield infrastructure in the implementation of the proposed mine-well technology for oil production at the late stage of operating existing fields. This goal is achieved by the fact that in the method of mine-well production, including major mining operations for opening an oil and gas deposit with mine shafts and main underground mining and preparatory workings, preparation of mining and preparatory workings of excavation-producing well blocks of an oil deposit, drilling a pressure-stimulating oil recovery system formation of wells, drilling of production wells with horizontal sections of the wellbore being carried out in the formation, production work on well production is difficult entrained oil using hydraulic fracturing of the reservoir, anhydrous effects of thermal effects on the reservoir and physico-chemical displacement of oil, separation of production of producing wells into oil and associated petroleum gas, a system of injection-stimulating oil recovery wells in extraction and production well blocks is formed by drilling wells along formation from underground mining workings, and production wells are drilled from the surface or directly from mining workings excavated borehole blocks with conventional or branched horizontal sections of the wellbore or select production wells from the number of vertical wells already existing above the reservoir, drilling only their horizontal sections in a given configuration, methane is extracted from associated petroleum gas during oil separation, which is used to generate electrical energy for gas turbine power plant, and the propane-butane component of associated petroleum gas is liquefied in underground conditions and used as a displacing working th agent injected into the reservoir through a system of injection-stimulating wells.

This goal is also achieved by the fact that the technological complex of mine-borehole production of hard-to-recover oil, including mine shafts, main underground mining and preparatory workings, equipment for drilling and operating production wells with horizontal sections of the trunk in the production reservoir, equipment for drilling along the formation from underground mining preparatory workings of injection-stimulating wells, technical means of oil refining and separation, heat and power equipment for use associated petroleum gas, equipped with a unit for the separation of associated petroleum gas into dry stripped gas - methane and a wide fraction of light hydrocarbons connected to the unit for oil separation, the output of a wide fraction of hydrocarbons from the unit for associated petroleum gas separation through a trunk gas pipeline is connected to a propane-butane liquefaction device installed in the near-barrel yard mixture to which through an intermediate storage tank, a switch device for liquefied gases, a distribution pipe and Handy devices are connected to injection-stimulating wells of extraction and extraction blocks of an oil deposit, and in the case of developing an oil reservoir with a high viscosity of oil, the complex is also supplied with an underground heat source with electric power, which is connected to a circulation circuit of heat-carrying fluid medium of tubular heat exchangers, installed in injection-stimulating wells. The proposed method and technological complex for the production of hard-to-recover oil is depicted and illustrated by the illustrations presented in FIG. 1-9.

In FIG. 1 shows: 1 - productive formation of hard-to-recover oil; 2 ₁ - the main shaft of the shaft; 3 - mine roundabout yard; 4 - capital and precinct mining and development workings; 5 - installation of separation (separation) of associated petroleum gas into methane (dry stripped gas - SOG) and the fatty fraction of associated petroleum gas (BFLH), containing mainly propane-butane mixture; 6 - underground installation for liquefying a wide fraction of light hydrocarbons; 7 - pipeline; 8 - intermediate storage capacity (tank) of liquefied propanobutane mixture - a component of associated petroleum gas; 9 - device for injection (supply) of liquefied gases into the reservoir; 10 - stem cryogenic pipeline of liquefied inert gases; 11 - stem electric cable; 12 - trunk gas pipeline (NGL); 13 - installation of the final oil preparation (output devices for oil shipment are not conventionally shown); 14 - combined device (source) of heating and circulation of a heat-carrying fluid in the reservoir (when producing highly viscous oil); 15 ₁ -15 _n - injection transverse (by reservoir thickness) wells for supplying liquefied gases to the drainage system of mining blocks; 16 ₁ -16 _n - valve devices; 17 - distribution pipeline of liquefied gases; 18 - producing well (vertical section of the wellbore of the producing well); 19 is a horizontal section of the wellbore of a producing well (horizontal well); 20 - wellhead equipment of the producing well; 21 - flow pipeline "crude"oil; 22 - gas turbine; 23 - air compressor; 24 - an electric generator; 25 - production installation (source) of low-boiling liquefied gas of nitrogen and (or) methane.

In FIG. 2, 1-14, 18-25 represent and designate one-to-one all the same devices and objects as in FIG. 1, with the exception of the following differences: 4 ₁ and 4 ₂ - local mining and preparatory workings of a borehole extraction and production column; 15 ₁ -15 _n-1 - injection-stimulating wells of the drainage system; 15 _n - borehole return flow of the circulation circuit of the heat-carrying fluid; 16 ₁ -16 _n-1 - distribution pipeline for injection of liquefied propanobutane mixture into the reservoir; 17, 17 ₁ , 17 ₂ - distribution, prefabricated and return pipelines, respectively, of the flow of heat-carrying fluid (working fluid) of the circulation circuit.

In FIG. 3, 1 to 25 show and designate all the same objects and devices, respectively, as in FIG. 2, and also additionally presented: 21 (26) - discharge pipelines of "crude"oil; 27 ₁ -27 _n-1 are the external pipes of the downhole heat exchangers and 28 ₁ -28 _n-1 are the internal pipes of the downhole heat exchangers.

In FIG. 4 shows an example of the implementation of the proposed method and complex of equipment as applied to the scheme (satellite image) of the existing Agan oil field for developing productive formations with low permeability reservoirs according to the scheme shown in FIG. one.

In FIG. 5 shows an example of the implementation of the proposed method and complex of equipment as applied to the scheme (satellite image) of the existing Agan oil field for developing productive formations of difficult to recover, for example, highly viscous oil according to the scheme shown in FIG. 2.

In FIG. 6 shows an example of an implementation of the proposed method and complex of equipment as applied to the scheme (satellite image) of the existing Vakha oil field for developing productive formations according to the scheme shown in FIG. 3.

In FIG. 7 shows an embodiment of an example of the proposed method and complex of equipment for working out productive formations according to the scheme depicted in FIG. 3, and with the drilling of all wells along the precast mining workings 4 ₁ and 4 ₂ only in terms of the thickness of the productive formation (without horizontal sections of the wellbore) and structurally combined execution of the wells of the drainage system, but generally implementing the technology of operation shown in FIG. 3.

In FIG. 8 shows an example of the implementation of the proposed method and complex of equipment for practicing productive formations according to the scheme depicted in Fig. 3, and with drilling all wells along precinct mining and development workings 4 ₁ and 4 ₂ only in terms of productive formation thickness (without horizontal sections of the wellbore ), but with one or another scheme of alternating injection-stimulating and production (injection) wells and their structurally separate execution of wells.

In FIG. 9 shows an example of an implementation of the proposed method and a set of equipment for working out productive formations according to the scheme shown in Fig. 3, and with drilling all wells along precinct mining and development workings 4 ₁ and 4 ₂ in terms of productive formation power and with counter-horizontal sections of the trunk structurally separate production wells.

The proposed method and technological complex for the production of hard-to-recover oil are implemented as follows. At the same time, hard-to-recover oil is understood as unconventional oil sources and resources, such as, first of all, oil and gas shale deposits (plei) and deposits of highly viscous heavy (bitumen) oil, and residual oil from fields with traditional reservoirs at the late stage of developing these reserves.

Example 1

Let there be a shale oil and gas bearing reservoir 1 to be developed and developed (Fig. 1), located sufficiently deep from the earth’s surface, as a result of which hydrocarbon production from such a deposit is carried out by usual technological methods available and known at a given moment in the production of shale oil by technical and economic considerations unacceptable. Then, according to the proposed method, the opening of the shale deposit (reservoir) 1 is carried out by vertical shaft shafts: 2 ₁ — the main shaft shaft and 2 ₂ — the auxiliary (ventilation) shaft, which in FIG. 1 conventionally not shown. The opening horizon (the depth of the mine shafts) is taken on the basis of the need (desirability) to get as close as possible to the productive formation and the possibility of maintaining at an acceptable level of technical and economic parameters and the conditions for the sinking and operation of vertical mine shafts. It can be assumed that this will be a depth of the order of 1000-1200 m. On the opening horizon, a round-barrel yard 3 is constructed in the usual manner and mining 4 is carried out.

The preparation of the reservoir for development, the formation of an effective drainage system in the reservoir and its "hydraulic fracturing" based on the requirements of ensuring the greatest possible simplification of the aggregate of underground technological operations, the composition and structure of underground equipment are carried out as follows. On the day surface there is a unit 5 for separating (separating) associated petroleum gas into methane (dry stripped gas - SOG) and a fatty fraction of associated petroleum gas (BFLH), containing mainly propane-butane mixture. Underground in the near-barrel yard 3 is an underground installation 6 for liquefying a wide fraction of light hydrocarbons. Installation 6 is connected by a pipeline 7 to the intermediate storage capacity (reservoir) 8 of the liquefied propane-butane mixture-component of associated petroleum gas located here, to which a device for pumping (supplying) liquefied gases to the reservoir 9. A device for supplying liquefied gases 9 is provided with an additional switched input, connected to the cryogenic pipeline 10 laid along the barrel 2 ₁ for supplying other (if necessary) liquefied gases to the reservoir. To power the installation 6 for LNGF liquefaction in the barrel 2 ₁ , a trunk electric cable 11 and a trunk gas pipeline 12 are laid, which through the corresponding output of the surface separation unit 6 is connected to the surface installation of the final oil preparation 13. Moreover, in other variants and examples of the proposed method and technological complex, the device for supplying liquefied gases 9 may include, as it were, a combined and structurally separate device (source) of impacts 14 to increase oil recovery productive formation.

The creation of an effective drainage system for highly productive and sufficiently complete extraction of shale oil from the reservoir is carried out by drilling from the preparatory development 4 systems of transverse (reservoir thickness) injection wells - holes of small diameter 15 ₁ -15 _n with a relatively small pitch (distance) between them and as a whole being equipped similarly to conventional oil production wells, i.e. having (if necessary) a casing perforated in the zone of the reservoir, sealing devices, preventers, etc. Injection wells 15 ₁ -15 _n through valve devices 16 ₁ -16 _n and a distribution pipe of liquefied gases 17 are connected to the output of the installation 9 (14). At least one production well is drilled from a day surface that has a vertical section of the wellbore 18, as well as an extended horizontal section of the wellbore 19 (horizontal well) traversed in the lower part of the reservoir. The production well is usually equipped with wellhead equipment, including pumping equipment for lifting oil, 20, which is connected through the flow pipeline of the crude oil to the final oil preparation device 13.

A gas turbine electrical installation (station) is also installed on the day surface, including a gas turbine 22 connected to an associated petroleum gas separation (separation) installation. As usual, an air compressor 23 and an electric generator 24 are installed on the shaft of the gas turbine 22, the output power of which is used as for the needs of the technological complex, in particular, to power the installation (source) 25 for the production of low-boiling liquid nitrogen gas and (or ) methane, and to power external electrical consumers.

After all the necessary mining, construction, installation and commissioning works, the operation of the technological complex for the production of shale oil is carried out as follows. Associated petroleum gas (APG) from the final oil preparation unit 13 enters the separation unit 5, in which methane is separated, which is usually contained in an amount of about 50-60% of the APG hydrocarbon gas. This methane is fed to a gas turbine power plant to generate electrical energy, and the rest of the separated associated petroleum gas, i.e. NGL through the trunk gas pipeline 12 enters the liquefaction unit 6 and then through the pipeline 7 in the liquid phase (in liquefied form) is accumulated in the tank (tank) 8. As part of this fraction (as NGL), propane gases are known to be found in the greatest amount and butane, and it is the liquefied mixture of hydrocarbon gases that make up BFLH that is used as the working fluid for the "hydraulic fracturing" of the reservoir. For this, from the source (reservoir) 8 by the injection device 9, the liquefied propane-butane mixture through the distribution pipe 17 and valve devices 16 ₁ -16 _n is supplied to the injection wells 15 ₁ -15 _n . The liquefied hydrocarbon gases injected into the micropores of the reservoir produce a piston effect (displacement) on the hydrocarbons (oil and gas) contained in them, and as the liquefied gases inevitably transfer from the liquid phase to the gaseous phase, the formation pressure also increases, causing the contained pressure in the reservoir, hydrocarbons move to the horizontal wellbore 19 of the producing well, wherefrom the well’s production (gas-oil mixture) through the vertical wellbore 18 and wellhead The food 20 rises (is pumped out) to the surface of the day and then the raw oil flow line 21 is fed for purification, degassing and final preparation in the device 13 for delivery to consumers. Associated petroleum gas from the latter enters the separation device 5, thereby closing the oil extraction technological cycle. In this case, methane gas extracted in the installation 5 from the associated gas is fed to a gas turbine 22 with an air compressor 23 and an electric generator 24 and is used as fuel for generating electric energy used to power underground consumers via a trunk electric cable 11. In case of need, the installation 25 can also liquefied natural gases, such as liquid nitrogen or liquid carbon dioxide, are used to ensure the safe and efficient operation of the mine complex oil bulls (explosion and fire safety, increasing the efficiency of hydraulic fracturing, oil recovery, etc.). In this case, the liquefied gases generated on the day surface are fed into the underground space of the technological complex via the cryogenic trunk pipeline 10 through the device 9 (14) - FIG. 1. In general, the principal advantage of this embodiment of the proposed method and technological complex for the production of shale oil is the possibility of economically acceptable development of shale oil and gas bearing deposits that lie at depths significantly exceeding the value of the mine opening horizon and preparation of the productive formation for development (1000-1200 m). The thickness (thickness) of the roof of the reservoir, as can be seen from FIG. 1, does not directly affect the feasibility and operability of the proposed technical and technological solutions, and in fact, there is thus the possibility of mining productive formations that occur at significantly greater depths.

Example 2

Let there be a deposit of highly viscous heavy (bituminous) oil, the productive layer of which lies at a depth up to the rational level indicated in Example 1 above - the mine opening horizon and having a thickness (thickness) of 10-15 m. It is known that it is necessary to extract such highly viscous oil by acting in one way or another on the reservoir, reduce the viscosity of the oil to such a level that its mobility becomes sufficient to move through the reservoir to production wells. Among these effects include, first of all, heating the reservoir and artificial saturation of viscous oil with highly mobile gaseous working agents to create and maintain the in-situ pressure at the required level. According to the proposed method, this is as follows (Fig. 2). On the horizon of the mine opening and preparation of the extraction-well column, not one, but two approximately parallel mining and development workings 4 ₁ and 4 ₂ pass at a distance of several hundred meters from each other. Between these workings with a step (distance from each other) of several tens of meters, injection-stimulating wells 15 ₁ -15 _{n-1 are} drilled and equipped, as in example 1 (Fig. 1), perforated with casing in the zone of the productive formation, and also additionally install tubular heat-exchange elements in them, which are connected by pipelines 16 ₁ -16 _n-1 at the production 4 ₁ and 17 ₁ at the production 4 ₂ and close them through the same well 15 _n and pipe 17 ₂ into the circulation circuit of the heat-carrying fluid like ordinary water how's it going etsya and in district heating systems, connected to the heat source in the form of an electric boiler 14 which is supplied with the surface of stem 11, the electric cable.

It is also significant here that the injection-stimulating wells 15 ₁ -15 _n-1 are drilled in the upper part of the reservoir 1, and the liquefied propane-butane mixture obtained, as in example 1, by the injection device 9 is fed into the annular gaps between the perforated casing pipes wells 15 ₁ -15 _n-1 and installed inside their tubular heat-exchange elements of the circulation circuit for heating the reservoir. At least one production well, as in example 1, is drilled from the day surface and has the same design — a vertical section of the well 18 and a horizontal section 19, passed in the lower part of the reservoir through the stimulating wells 15 ₁ -15 _n-1 . Ultimately, the borehole drainage system of the reservoir thus created and continuous thermogas-liquid anhydrous exposure to it ensures the preservation of the reservoir properties of the reservoir (reservoir) and, as a result, ensures a high degree of oil recovery (reservoir recovery), since it is the displacing (acting) ) working agent in the proposed method, the formation fluids themselves (propanobutane mixture) are used, which are an integral part of the extracted carbohydrate Orodov during the development of oil and gas deposits. Otherwise, the proposed method and the operation of the technological complex for its implementation are implemented similarly to the more detailed description set forth in Example 1 above.

Example 3

Let the oil-and-gas-bearing deposit of a sufficiently large (several tens of meters) power be subject to mining, which also lies at a depth significantly exceeding the rational (acceptable for technical and economic reasons) horizon of mine opening and preparation for borehole mining and containing hard-to-recover oil. This can be, as in example 2, high-viscosity heavy (bitumen) oil or, for example, residual (non-recoverable) oil at the late - final stage of exploitation of oil fields with traditional reservoirs. The proposed method and technological complex of equipment in this case are implemented and work according to the scheme shown in FIG. 3, and generally remain the same as described above in examples 1 and 2. The differences here only boil down to the following. As in example 1, for the preparation of a well production block, only one development 4 ₁ is passed. From this production, injection-stimulating wells 15 ₁ -15 _n-1 are drilled, but they are not drilled in the plane of the reservoir, but in terms of its capacity, i.e. across the strike of the formation. In this case, the injection-stimulating wells themselves are supplied (Fig. 3) with pipe-in-pipe borehole heat exchangers having external tubular elements 27 ₁ -27 _n-1 with the end closed at the bottom and internal tubular elements 28 ₁ -28 _n-1 with open lower parts to allow circulation of heat transfer fluid through the wells, as shown in FIG. 3 arrows. Downhole pipe-in-pipe heat exchangers by pipelines 17 and 17 ₂ at the development 41 are connected together and connected to an electric source of thermal energy 14 and forming with it a closed circulation loop of the heat-carrying fluid. During the development of residual oil from a previously flooded oil field, the “productive formation” is processed by injecting liquefied carbon dioxide from the plant 25 through a cryogenic stem pipeline 10 into it from the surface 25, as the most effective displacing working agent for “flushing” a highly watered oil reservoir. The rest of the proposed method is implemented and the technological complex works as described above in examples 1, 2.

Example 4

An important advantage of the proposed method and technological complex is the possibility of their use for involvement in the development of previously undeveloped productive formations with hard-to-recover reserves at existing oil fields, but which have already entered the stage of late operation. In FIG. Figure 4 shows a satellite image of the Aganskoye oil field in the Khanty-Mansiysk Autonomous Okrug - Yugra with the surface part of the technological complex located in a suitable place of the field (in Fig. 4 they are outlined by a dot-and-dot line), as well as the underground part represented by all the same objects and devices that and in FIG. 1. In this case, at least one of the existing vertical wells 18 is used, which is additionally drilled by the horizontal section 19, and the existing flow and oil field pipelines 21 and oil treatment plants 13 are used. But, of course, additional opening and preparation of the reservoir are required included in the development, as well as the construction of the injection well system 15 ₁ -15 _{n of the} drainage system, installation and commissioning of other production facilities, as described in paragraph Rimer 1. An even more radical solution to the problem of “secondary” (re) exploitation of already used oil fields can be the use of the proposed method and technological complex of equipment on the example of the same Aganskoye oil field according to the scheme shown in FIG. 5. Here, in succession, parts are used the entire existing network of oil wells operating in their usual mode for, and additionally, mine opening and preparation of production pillars (extraction blocks) are carried out by two mining and preparatory workings 4 ₁ and 4 ₂ , passed approximately parallel to the rows of existing oil wells at a distance spanning at least one row of existing wells. Then, in the upper part of the previously developed, for example, by flooding, productive deposits, a system of injection-stimulating wells 15 ₁ -15 _{n-1 is} constructed in the plane of the formation (drilled and equiped), as in example 2 (Fig. 2), and they are also installed put into operation and other equipment and installations provided for by the proposed method. In General, the production process of re-development of the field and oil production is carried out as described above, including examples 1-3. Ultimately, given that usually the final (actual) oil recovery factor (CIN) is very often below the approved design values, re-development of oil fields by the proposed method can have a serious economic effect in this case. For only explored and re-operating oil fields of hard-to-recover oil with oil and gas deposits of sufficiently high power, such as for the Vakhsky oil field in the Tomsk region, the use of the proposed method and technological complex according to the scheme shown in Fig. 6 can also be preliminarily recommended. . As can be seen, here we use the system of injection-stimulating wells previously drilled in reservoir power and equipped with borehole pipe-in-pipe heat exchangers, which was previously considered in Example 3 (Fig. 3).

Example 5

As you know, the main achievements of the existing purely borehole oil production technology and, first of all, the development of shale oil resources are associated with technologies of horizontal drilling and hydraulic fracturing of productive formations, although the so-called horizontal drilling of oil wells even from the surface is more expensive and technologically quite difficult. Therefore, within the framework of the proposed method, variants of its implementation are possible, in which both production and injection-stimulating wells are drilled in rows from underground mining and development workings with only vertical shafts, i.e. with the simplest (usual) trajectory. Moreover, as shown in FIG. 7, to reduce the amount of drilling work, structurally stimulating wells 15 ₁ -15 _n and production wells 18 ₁ -18 _n can be combined and used as necessary in one or another operating mode, respectively. In contrast, as shown in FIG. 8, in the rows of wells drilled at preparatory workings 4 ₁ and 4 ₂ , the injection-stimulating and producing wells can alternate with each other in a predetermined ratio. In FIG. 8, these wells alternate simply through one, and, as usual, production wells can be used, if necessary, as injection wells to supply one or another acting agent (working fluid) to the reservoir. In order to reduce the volume of mining operations to conduct preparatory workings by increasing the width of mining and production well blocks, drilling in rows of production wells can also be carried out using horizontal sections of the barrel that are opposite to each other from adjacent preparatory workings 4 ₁ and 4 ₂ , as shown in FIG. 9. Otherwise, the proposed method and technological complex are implemented and operate, as described above in examples 1-5, with appropriate consideration of the specific features of specific oil fields.

In conclusion, it should be pointed out that the proposed method for extracting hard-to-recover oil and the technological complex of equipment for its implementation are quite universal and can be used to develop complex oil and gas fields, such as, for example, the Van-Yeganskoye oil field in Western Siberia, on the oil and gas floor of which At various depths, there are productive formations of high-viscosity (heavy) oil, as well as medium-viscosity formations, light oil formations and other complicating factors. Of particular interest are the proposed method and technological complex of equipment for developing oil fields with conventional (traditional) reservoirs, worked out by water flooding and entered the late stage of operation, since, on the one hand, their further operation becomes unprofitable due to the high water cut of well products, and , on the other hand, the oilfield infrastructure available on them can be effectively involved in the transition, as it were, to re-mining the field, it makes it possible to significantly reduce initial capital costs for the implementation of these methods and complex equipment.

Used sources

1. Zapadinsky A.L. A method of developing oil fields. - RF patent №2181158 from 09/07/2000 - Patent holder: A. Zapadinsky

2. Zapadinsky A.L. Complex for the development of hydrocarbon deposits (options). - RF patent No. 2181159 of March 15, 2001 - Patent holder: A. Zapadinsky

3. Zapadinsky A.L. Complex for the development of an oil or gas condensate field (options). - RF patent No. 2208138 dated 12/20/2001 - Patent holder: A. Zapadinsky

4. Graifer V.I., Lysenko V.D. A method of developing an oil reservoir. - RF patent No. 2238399 dated January 27, 2003 - Patent holder: - OJSC RITEK.

5. Khisamov P.C. and others. A method of developing an oil reservoir by horizontal wells. - RF patent No. 2287674 dated December 16, 2006 - Patent holder: OAO Tatneft named after V.D. Shashina.

6. Khisamov P.C. and others. A method of developing an oil reservoir with a clay reservoir. - RF patent No. 2527949 dated November 7, 2013 - Patent holder: OAO Tatneft named after V.D. Shashina.

7. Khisamov P.C. and others. A method of developing a heterogeneous oil field. - RF patent No. 2535762 dated 01/17/2013. - Patent holder: OAO Tatneft named after V.D. Shashina.

8. Khisamov P.C. et al. A method for developing an oil reservoir in multilateral horizontal wells. - RF patent No. 2544207 dated 03.03.2014. - Patent holder: OAO Tatneft named after V.D. Shashina.

9. Ruzin L.M. and others. Thermal mine method of developing a fractured reservoir of high-viscosity oil. - RF patent No. 2535326 of 03/27/2013. - Patent holder: Federal State Budgetary Educational Institution of Higher Professional Education "Ukhta State Technical University".

10. Fayzullin I.N. and others. A method of developing deposits of high viscosity and heavy oil with thermal effects. - RF patent No. 2537456 dated 2910.2013. - Patent holder: Tatneft Open Joint-Stock Company named after V.D. Shashina.

11. Kondyrev B.I. et al. Method for fracturing rocks. - RF patent No. 2280163 dated 12/14/2014. - Patent holder: Far Eastern State Technical University.

12. Ilyusha A.V. and others. A method of developing shale oil and gas deposits and a technological complex of equipment for its implementation. - RF patent No. 2547847 dated 02.20.2014. - Patent holder: Federal State Budgetary Educational Institution of Higher Professional Education “State University of Management” (GUU) - prototype.

Claims (2)

1. The method of mine-borehole extraction of hard-to-recover oil, including capital mining operations to open the oil and gas bearing mine shafts and the main underground mining and preparatory workings, the preparation of mining and preparatory workings of excavation-producing well blocks of the oil deposit, drilling a system of injection stimulating oil recovery wells, drilling of production wells with horizontal sections of the wellbore being carried out in the formation, production work on well production of hard-to-recover oil using hydraulic fracturing of the reservoir, anhydrous effects of thermal effects on the reservoir and physico-chemical displacement of oil, separation of production of production wells into oil and associated petroleum gas, characterized in that the system of injection-stimulating oil recovery of wells in excavation-producing well blocks is formed by drilling wells in the reservoir from underground mining workings, and production wells are drilled from the surface or directly from mining workings production wells with conventional or branched horizontal sections of the wellbore, or production wells are selected from the number of vertical wells already existing above the reservoir, drilling only their horizontal sections in a given configuration, methane is extracted from associated petroleum gas during oil separation, which is used to generate electrical energy in a gas turbine power plant, and the propane-butane component of associated petroleum gas is liquefied in underground conditions and used as a displacing working agent injected into the reservoir through a system of injection-stimulating wells. 2. The technological complex of mine-borehole production of hard-to-recover oil, including mine shafts, main underground mining and development workings, equipment for drilling and operating production wells with horizontal sections of the trunk in the production well, equipment for drilling through the formation from underground mining workings stimulating wells, oil refining and separation equipment, heat and power equipment for the use of associated petroleum gas, characterized in that the complex is equipped with a unit for the separation of associated petroleum gas into dry stripped gas - methane and a wide fraction of light hydrocarbons connected to an oil separation unit, the outlet of a wide fraction of hydrocarbons from the unit for associated petroleum gas separation through a trunk gas pipeline is connected to a propane-butane mixture liquefaction device installed in the near-barrel yard, to which through an intermediate storage tank, a switch device for liquefied gases, a distribution pipe and valve The properties are connected to injection-stimulating wells of extraction and extraction blocks of an oil deposit, and in the case of developing an oil reservoir with a high viscosity of oil, the complex is also equipped with an underground heat source with electric power, which is connected to a circulation circuit of heat-carrying fluid medium of tubular heat exchangers installed in injection-stimulating wells.

Images