EGS-based geothermal vertical well-horizontal well development method, device, equipment and medium

Abstract

The invention discloses an EGS-based geothermal vertical well-horizontal well development method. The method comprises the following steps: selecting a waste horizontal well; the optimal utilization length of the abandoned horizontal well is determined based on the regional water taking amount demand statistical value; a vertical well is deployed within the range of the optimal utilization length of the abandoned horizontal well, and a vertical well water taking and horizontal well recharge well pattern is formed; stages are divided based on indoor physical simulation geothermal development, stage parameters in the heat exchange process are optimized, and the vertical well water taking amount of different stages is calculated. The invention further provides an EGS-based geothermal vertical well-horizontal well development device, equipment and a medium. The method is high in practicability, the purposes of recycling the waste horizontal well and improving the buried hill heat storage utilization rate can be achieved, and a new buried hill geothermal development mode is established.

Description

Technical Field

[0001] The present invention relates to the field of geothermal development technology, and in particular to an EGS geothermal vertical well-horizontal well development method, device, equipment and medium. Background Art

[0002] Enhanced Geothermal Systems (EGS) uses artificial means to establish high-permeability artificial heat reservoirs in low-permeability and ultra-low-permeability high-temperature geothermal resources, and then injects low-temperature fluid media to replace the heat energy in the low-permeability and ultra-low-permeability heat reservoirs. The most critical technology of EGS is reservoir transformation, the purpose of which is to establish a large volume of water storage layers in low-permeability rocks, so that the original natural fractures are displaced or new fractures are formed, so that the injection well and production well system can establish appropriate connectivity. Commonly used reservoir transformation methods include hydraulic fracturing, thermal stimulation and chemical stimulation. Hydraulic fracturing is the most important means of EGS reservoir transformation. At present, almost all EGS projects abroad use hydraulic fracturing technology to form heat exchange structures, such as FentonHill in the United States, Soultz in France, Hijiori in Japan, etc.

[0003] The exploration of buried hill oil and gas is an important part of the stable production of tens of millions of tons of oil fields. In the history of Liaohe Oilfield, multiple horizontal wells were designed and deployed in combination with the development of buried hills. These horizontal wells adopted water injection development in the early stage to achieve oil and gas displacement and play an important role in improving the recovery rate of buried hill oil reservoirs. The vertical depth of the horizontal section of these horizontal wells is below 4000m, and the measured formation temperature is above 135 degrees. As the development of the oil field enters the middle and late stages, these horizontal wells have gradually lost their role in oil and gas development. Due to the high formation temperature of the layer section where they are located, they have great potential for geothermal development. Therefore, how to use the original horizontal wells to achieve efficient geothermal development has become an important potential direction.

[0004] Therefore, there is a need in the prior art for the design of a vertical well water extraction and horizontal well reinjection development method based on EGS geothermal. Summary of the invention

[0005] In view of this, the purpose of the embodiments of the present invention is to propose a geothermal vertical well-horizontal well development method, device, equipment and medium based on EGS, to establish a geothermal vertical well water extraction horizontal well reinjection development model, which can achieve the purpose of reusing abandoned horizontal wells and improving the utilization rate of buried mountain heat storage.

[0006] Based on the above purpose, an embodiment of the present invention provides a method for developing geothermal vertical wells and horizontal wells based on EGS, including the following steps:

[0007] Select abandoned horizontal wells;

[0008] Determine the optimal utilization length of abandoned horizontal wells based on the statistical value of regional water demand;

[0009] Deploy vertical wells within the optimal utilization length of abandoned horizontal wells to form a vertical well water extraction and horizontal well recharging well network;

[0010] Based on the indoor physical simulation, geothermal development is divided into stages, the stage parameters in the heat exchange process are optimized, and the vertical well water intake in different stages is calculated.

[0011] In some embodiments, selecting the abandoned horizontal well includes:

[0012] Obtain exploration data of buried hill thermal reservoirs and select abandoned horizontal wells based on the exploration data.

[0013] In some embodiments, the exploration data includes: reservoir burial depth, formation temperature in the middle of the reservoir, formation intervals, number of horizontal wells, water breakthrough depth, and water breakthrough formation temperature.

[0014] In some embodiments, determining the optimal utilization length of abandoned horizontal wells based on regional water demand statistics includes:

[0015] In some embodiments, the optimal utilization length of the abandoned horizontal well is determined based on the statistical value of the regional water intake demand and the formation parameters, oil well parameters, and pressure values.

[0016] In some embodiments, deploying vertical wells within the optimal utilization length of abandoned horizontal wells includes:

[0017] The diameter is deployed at the toe of the range of optimally utilized lengths of abandoned horizontal wells.

[0018] In some embodiments, the indoor physical simulation geothermal development is divided into five stages, including fluid replacement period, geothermal utilization steep decline period, geothermal utilization slow decline period, geothermal utilization stable period, and geothermal depletion period.

[0019] In some embodiments, optimizing the stage parameters in the heat exchange process by dividing the geothermal development into stages based on indoor physical simulation includes:

[0020] During the fluid replacement period, the vertical well water intake is calculated based on the relationship between fluid temperature and formation temperature;

[0021] During the period of steep decline, slow decline and stable utilization of geothermal energy, vertical well water extraction and horizontal well recharge development are carried out based on the U-shaped well development model, and the vertical well water extraction volume is adjusted based on the different requirements of heat exchange power in different periods;

[0022] During the geothermal depletion period, water withdrawal is zero.

[0023] In some embodiments, the calculation formula for the vertical well water intake during the fluid replacement period is:

[0024]

[0025] Where a is the formation length, m; h is the formation thickness, m; K is the formation permeability, D; L is the horizontal section length, m; P e , supply boundary pressure, MPa; P wf , bottom hole pressure, MPa; q, production (underground), m 3 / ks; R, total seepage resistance of horizontal well, mPa·s / (D·m); r w , oil well radius, m; μ, fluid viscosity, mPa·s.

[0026] In some embodiments, the formation segment includes four segments, the first segment is -2000 to -3000 m, the second segment is -3000 to -3500 m, the third segment is -3500 to -4000 m, and the fourth segment is below -4000 m.

[0027] In another aspect, the present invention provides an EGS geothermal vertical well-horizontal well development device, comprising:

[0028] A selection module, the selection module is configured to select abandoned horizontal wells;

[0029] A first optimization module, the first optimization module is configured to determine the optimal utilization length of the abandoned horizontal well based on the regional water intake demand statistics;

[0030] A simulation deployment module, the simulation deployment module is configured to deploy vertical wells within the optimal utilization length of abandoned horizontal wells to form a vertical well water intake and horizontal well recharging well network;

[0031] The second optimization module is configured to divide the geothermal development into stages based on indoor physical simulation, optimize the stage parameters in the heat exchange process, and calculate the vertical well water intake in different stages.

[0032] In some embodiments, the selection module is further configured to: obtain exploration data of buried hill thermal reservoirs, and select abandoned horizontal wells based on the exploration data.

[0033] In some embodiments, the exploration data includes: reservoir burial depth, formation temperature in the middle of the reservoir, formation intervals, number of horizontal wells, water breakthrough depth, and water breakthrough formation temperature.

[0034] In some embodiments, the formation layer includes four sections, the first section is -2000 to -3000 m, the second section is -3000 to -3500 m, the third section is -3500 to -4000 m, and the fourth section is below -4000 m.

[0035] In some embodiments, the first optimization module is further configured to:

[0036] The optimal utilization length of the abandoned horizontal well is determined based on the statistical value of the water intake demand in the area and the formation parameters, oil well parameters and pressure values.

[0037] In some embodiments, the simulation deployment module is further configured to:

[0038] The diameter is deployed at the toe of the range of optimally utilized lengths of abandoned horizontal wells.

[0039] In some embodiments, the indoor physical simulation geothermal development is divided into five stages: fluid replacement period, geothermal utilization steep decline period, geothermal utilization slow decline period, geothermal utilization stable period, and geothermal exhaustion period.

[0040] In some embodiments, the second optimization module is further configured to:

[0041] During the fluid replacement period, the vertical well water intake is calculated based on the relationship between fluid temperature and formation temperature;

[0042] During the period of steep decline, slow decline and stable utilization of geothermal energy, vertical well water extraction and horizontal well recharge development are carried out based on the U-shaped well development model, and the vertical well water extraction volume is adjusted based on the different requirements of heat exchange power in different periods;

[0043] During the geothermal depletion period, water withdrawal is zero.

[0044] In some embodiments, the calculation formula for the vertical well water intake during the fluid replacement period is:

[0045]

[0046] Where a is the formation length, m; h is the formation thickness, m; K is the formation permeability, D; L is the horizontal section length, m; P e , supply boundary pressure, MPa; P wf , bottom hole pressure, MPa; q, production (underground), m 3 / ks; R, total seepage resistance of horizontal well, mPa·s / (D·m); r w , oil well radius, m; μ, fluid viscosity, mPa·s.

[0047] According to another aspect of the embodiments of the present invention, there is provided a computer device, comprising: at least one processor; and a memory, wherein the memory stores computer instructions executable on the processor, and the instructions implement the steps of the above method when executed by the processor.

[0048] According to another aspect of the embodiments of the present invention, a computer-readable storage medium is provided, which stores a computer program that implements the above method steps when executed by a processor.

[0049] The present invention has at least the following beneficial technical effects:

[0050] The present invention provides a method, device, equipment and medium for the development of horizontal well recharge based on EGS geothermal vertical well water extraction, and specifically proposes a new means of geothermal development for recharge of abandoned horizontal wells in buried hills and auxiliary vertical well water extraction. The original horizontal top section mostly uses screen pipe completion. Due to the large contact area between the horizontal well and the heat storage section, the recharge effect of the previous vertical well can be greatly improved, and the problem of the recharge intensity of conventional vertical wells can be solved. Comprehensive analysis can realize the efficient development of buried hill geothermal. The present invention is highly practical and can realize the purpose of reusing abandoned horizontal wells and improving the utilization rate of buried hill heat storage, and establish a new model for buried hill geothermal development. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0052] FIG1 is a schematic diagram of the traditional EGS development provided by the present invention, wherein: Figure 1-A For the development of low-permeability and ultra-low-permeability thermal reservoirs in Fenton Hill, USA in the 1970s, Figure 1-B For the development of low-permeability and ultra-low-permeability thermal storage in Rosemanowes, UK, Figure 1-C Development of low-permeability and ultra-low-permeability thermal reservoirs in Hijiori, Japan;

[0053] Figure 2 A schematic diagram of an embodiment of the EGS geothermal vertical well-horizontal well development method provided by the present invention;

[0054] Figure 3 A schematic diagram of an embodiment of a F buried hill horizontal well drilled in the present invention;

[0055] Figure 4 A schematic diagram of an embodiment of a vertical well water extraction and horizontal well recharge development profile provided by the present invention;

[0056] Figure 5 A schematic diagram of a planar embodiment of a vertical well water extraction and horizontal well recharge development provided by the present invention;

[0057] Figure 6 A schematic diagram of an embodiment of a simulated heat exchange power curve diagram at different stages provided by the present invention;

[0058] Figure 7 A schematic diagram of an embodiment of an EGS geothermal vertical well-horizontal well development device provided by the present invention;

[0059] Figure 8 A schematic diagram of an embodiment of a computer device is provided for the present invention;

[0060] Fig. 9 A schematic diagram of an embodiment of a computer-readable storage medium provided by the present invention. DETAILED DESCRIPTION

[0061] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field of the present invention; the terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. For example, the directions or positions indicated by the terms "length", "width", "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directions or positions shown in the drawings, which are only for the convenience of description and should not be understood as limitations on the present technical solution.

[0063] The terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions; the terms "first", "second", etc. in the specification and claims of the present invention or the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0064] In addition, reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0065] FIG1 is a schematic diagram of the traditional EGS development provided by the present invention, wherein Figure 1-A The following is the development of low-permeability and ultra-low-permeability thermal reservoirs in Fenton Hill, USA in the 1970s, which had problems such as low output flow (5-7L / S) (Duchane and Brown, 2002) and difficulty in connecting injection and production wells. Figure 1-BThe figure shows the development of low-permeability and ultra-low-permeability thermal reservoirs in Rosemanowes, UK. The hydraulic fractures are mainly shear fractures, which depend on the reactivation of natural fractures. Excessive hydraulic fractures may cause large hydraulic fractures to connect two wells, causing short circuits and water channeling. Figure 1-C The figure shows the development of low-permeability and ultra-low-permeability thermal reservoirs in Hijiori, Japan. The direction of the fracture and the ground stress will change in places far away from the wellbore, and the distance between two wells will cause a short circuit. Therefore, the method of the present invention is combined with the completed buried hill horizontal wells in Liaohe Oilfield for later transformation and geothermal development, which effectively solves the problem of poor effect under the traditional EGS mode and realizes the reuse of abandoned horizontal wells in the oilfield.

[0066] like Figure 2 The present invention provides a method for developing horizontal well recharge based on EGS geothermal vertical well water extraction, including the following steps:

[0067] S1. Select abandoned horizontal wells;

[0068] S2. Determine the optimal utilization length of abandoned horizontal wells based on the statistical value of regional water intake demand;

[0069] S3, deploying vertical wells within the optimal utilization length of abandoned horizontal wells to form a vertical well water intake and horizontal well recharging well network;

[0070] S4. Based on the indoor physical simulation, the geothermal development is divided into stages, the stage parameters in the heat exchange process are optimized, and the vertical well water intake in different stages is calculated.

[0071] like Figure 3 The figure shows a schematic diagram of an example of a completed horizontal well in F buried hill. F buried hill is located adjacent to Panjin City, with a large demand for regional heating. The nearby heat station supplies geothermal energy to an area of ​​about 8 million square meters per year. The formation section includes four sections, the first section is -2000~-3000m, the second section is -3000~-3500m, the third section is -3500~-4000m, and the fourth section is below -4000m. The F buried hill oil reservoir is buried at a depth of 2335~4670m, and the formation temperature in the middle of the reservoir reaches 118℃. Relying on the existing well network and using the middle and lower sections of the flooded wells, we explored and carried out deep natural bottom water geothermal development and utilization experiments to achieve a win-win situation of oil and heat co-production and energy saving and consumption reduction.

[0072] Furthermore, in S1, the exploration data of buried hill thermal reservoirs are obtained, and abandoned horizontal wells are selected based on the exploration data. The exploration data include reservoir burial depth, formation temperature in the middle of the reservoir, formation interval, number of horizontal wells, water breakthrough depth and water breakthrough formation temperature. Abandoned horizontal wells are selected based on the exploration data. There are 8 water breakthrough horizontal wells in the block, and the water breakthrough position is mainly located in the lower part of III and IV, with a water breakthrough depth of 3930m and a formation temperature of 135℃. The example well of this achievement is H406 well, which is a development well of the main block. It was drilled on October 29, 2010, with a completion depth of 5438 meters and a screen pipe completion. The well section 4328.21-5438.0 meters (vertical depth 4207.5-4299.5m) was put into production in January 2011, with a horizontal section length of 992.25m. Initially, 70 pumps were in production, with a daily oil production of 0 tons. The well was shut down on August 4, 2013 due to drilling. On September 9, 2019, 56 pumps resumed production without oil, with a cumulative water production of 34,200 cubic meters. In summary, the well was converted from an abandoned well to a reinjection well.

[0073] Furthermore, due to the complexity of factors affecting the heat exchange effect in the entire geothermal development process, multiple constraints include horizontal well length and inner diameter, formation temperature, rock thermal conductivity, production casing, cement material, reinjection water temperature, system operating flow, etc., combined with indoor physical simulation, geothermal development is divided into five stages: fluid replacement period, geothermal utilization steep decline period, geothermal utilization slow decline period, geothermal utilization stable period, and geothermal depletion period. The main constraints are confirmed to be the horizontal well length and inner diameter.

[0074] Further, from the perspective of horizontal well productivity, for a specific heat reservoir, the productivity of a horizontal well is limited by two parameters: the length of the horizontal section and the inner diameter of the horizontal section. Due to the friction loss in the horizontal section of the horizontal well, a pressure drop occurs when hot water flows along the wellbore of the horizontal well. If the pressure loss in the horizontal section is very small relative to the reservoir pressure drop, in some embodiments, if the ratio of the horizontal section pressure loss to the reservoir pressure drop is 0 to 0.8, then the productivity of the horizontal well will increase with the length. In this case, the length of the horizontal well is determined to be the limiting factor; on the other hand, if the pressure loss in the horizontal section is equivalent to the pressure drop in the reservoir, in some embodiments, if the ratio of the horizontal section pressure loss to the reservoir pressure drop is 0.8 to 1.2, and the horizontal section length is increased, and the horizontal well productivity increases very little, then the inner diameter of the horizontal well is determined to be the limiting factor, and the horizontal well productivity increases very little with the length of the horizontal section.

[0075] However, the present invention utilizes abandoned wells, and after selecting abandoned horizontal wells, the inner diameter of the horizontal section is a fixed value, so the only factor considered is the length of the horizontal section.

[0076] Further, in S2, determining the optimal utilization length of the abandoned horizontal well based on the regional water intake demand statistics includes:

[0077] The optimal utilization length of the abandoned horizontal well is determined based on the statistical value of the water demand in the area, the oil production index of the horizontal well, and the production pressure difference. The calculation formula is:

[0078]

[0079] Where a is the formation length, m; h is the formation thickness, m; k is the formation permeability, D; l is the horizontal section length, m; P e , supply boundary pressure, MPa; P wf , bottom hole pressure, MPa; q, production (underground), m 3 / ks;r w , oil well radius, m; μ, fluid viscosity, mPa·s.

[0080] In the example, the statistical value of the regional water demand is 3600-4500m 3 / d, based on the statistical value of water intake demand in the area, it is determined that the optimal utilization length of the abandoned horizontal well is 800-1000m.

[0081] Taking the starting point of the horizontal section of the abandoned horizontal well as the origin, an X-coordinate axis is established along the extension direction of the horizontal section. Q(x) represents the flow rate at the x position. Based on the friction loss of the horizontal well, the following is calculated:

[0082]

[0083]

[0084]

[0085]

[0086]

[0087] Among them, J S , the oil recovery index of the horizontal well in the fractured reservoir; ε, pipe wall roughness, m; u o , viscosity, mPa·S; ρ o , volume coefficient; m 3 / m 3 ; d, horizontal well inner diameter, m; r w , horizontal well radius, m; ΔP, production pressure difference, MPa.

[0088] Furthermore, in S3, if Figures 4-5As shown in the figure, combined with the completed horizontal wells, the conductivity of the horizontal section is fully utilized, and vertical wells are deployed within the length of the horizontal well to extract water. In space, a development model is formed in which vertical wells are used to extract water at the toe of the horizontal well and the original horizontal wells are recharged. This method can effectively solve the problem of extraction and injection in the traditional geothermal development model of low-permeability and ultra-low-permeability high-temperature heat storage. Moreover, through the optimization of the first step, it can also solve the problems of short circuit and disconnection in the traditional EGS model, realize the reuse of abandoned horizontal wells, and improve the efficient development of buried hill geothermal resources.

[0089] Furthermore, in S4, geothermal development is divided into four stages based on indoor physical simulation: fluid replacement period, geothermal utilization steep decline period, geothermal utilization slow decline period, and geothermal utilization stable period. Phased parameter optimization design:

[0090] (1) During the fluid replacement period, the reinjected fluid has not yet broken through the production well, and the fluid temperature ≈ the formation temperature. The water intake of the vertical well during this stage is calculated using the formula.

[0091]

[0092] In the formula,

[0093] a, formation length, m;

[0094] h, formation thickness, m;

[0095] K, formation permeability, D;

[0096] L, horizontal segment length, m;

[0097] P e , supply boundary pressure, MPa;

[0098] P wf , bottom hole flowing pressure, MPa;

[0099] q, output (underground), m 3 / ks;

[0100] R, total seepage resistance of horizontal well, mPa·s / (D·m);

[0101] r w , radius of oil well, m;

[0102] μ, fluid viscosity, mPa·s.

[0103] (2) The geothermal utilization steep decline period, geothermal utilization slow decline period, and geothermal utilization stable period. In this stage, geothermal development enters the U-shaped well development mode, and the formation pressure coefficient is reduced to below 0.85. Figure 6The schematic diagram of the simulated heat exchange power curve is shown. Numerical simulation shows that during the 25-year heating period, the heat exchange power dropped from 3MW to 1.6MW, with a cumulative drop of more than 40%. The drop in geothermal utilization was 25% in the first three years, 15% in the slow drop period of geothermal utilization from 4 to 10 years, and 3% in the stable period of geothermal utilization from 11 to 25 years. In view of the different changes in heat exchange power in different periods, the vertical well water intake can be changed in combination with actual heating demand to achieve efficient development.

[0104] (3) During the geothermal depletion period, water withdrawal is zero.

[0105] On the other hand, the present invention also provides a vertical well-horizontal well development device based on EGS geothermal, such as Figure 7 As shown, including:

[0106] A selection module, wherein the selection module is configured to select abandoned horizontal wells;

[0107] A first optimization module, the first optimization module is configured to determine the optimal utilization length of the abandoned horizontal well based on the regional water intake demand statistics;

[0108] A simulation deployment module, the simulation deployment module is configured to deploy vertical wells within the optimal utilization length of abandoned horizontal wells to form a vertical well water intake and horizontal well recharging well network;

[0109] The second optimization module is configured to divide the geothermal development into stages based on indoor physical simulation, optimize the stage parameters in the heat exchange process, and calculate the vertical well water intake in different stages.

[0110] The device of the present invention is used to implement the above-mentioned development method. All functions and effects mentioned in the above-mentioned method can be achieved by the device of the present invention, so they are not described in detail.

[0111] Based on the above purpose, a third aspect of an embodiment of the present invention provides a computer device. Figure 8 FIG. 2 is a schematic diagram of an embodiment of a computer device provided by the present invention. Figure 8 As shown, the computer device of the embodiment of the present invention includes the following devices: at least one processor 021; and a memory 022, the memory 022 stores computer instructions 023 that can be executed on the processor, and the instructions implement the steps of the above method when executed by the processor.

[0112] The present invention also provides a computer-readable storage medium. Fig. 9 FIG. 2 is a schematic diagram of an embodiment of a computer-readable storage medium provided by the present invention. Fig. 9 As shown, the computer-readable storage medium 031 stores a computer program 032 that performs the above method when executed by a processor.

[0113] Finally, it should be noted that a person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program of the vertical well-horizontal well development method based on EGS geothermal can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, the storage medium of the program can be a disk, an optical disk, a read-only storage memory (ROM) or a random access memory (RAM), etc. The above-mentioned computer program embodiments can achieve the same or similar effects as the corresponding above-mentioned any method embodiments.

[0114] The above are exemplary embodiments disclosed in the present invention, but it should be noted that various changes and modifications may be made without departing from the scope disclosed in the embodiments of the present invention as defined in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.

[0115] It should be understood that, as used herein, the singular forms "a", "an" are intended to include the plural forms as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations including one or more of the associated listed items.

[0116] The serial numbers of the embodiments disclosed in the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0117] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the embodiments of the present invention as above, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. A geothermal vertical well-horizontal well development method based on EGS, characterized in that: include: Select abandoned horizontal wells; Determining the optimal utilization length of the abandoned horizontal well based on the regional water intake demand statistics; Deploy vertical wells within the optimal utilization length of the abandoned horizontal wells to form a vertical well water extraction and horizontal well recharging well network; Based on the indoor physical simulation, geothermal development is divided into stages, the stage parameters in the heat exchange process are optimized, and the vertical well water intake in different stages is calculated.

2. The EGS geothermal vertical well-horizontal well development method according to claim 1, characterized in that: The abandoned horizontal wells include: Exploration data of buried hill thermal reservoirs are obtained, and abandoned horizontal wells are selected based on the exploration data.

3. The EGS geothermal vertical well-horizontal well development method according to claim 2, characterized in that: The exploration data include: reservoir burial depth, formation temperature in the middle of the reservoir, formation intervals, number of horizontal wells, water breakthrough depth and water breakthrough formation temperature.

4. The EGS geothermal vertical well-horizontal well development method according to claim 1, characterized in that: The optimal utilization length of abandoned horizontal wells based on the statistical value of regional water demand includes: The optimal utilization length of the abandoned horizontal well is determined based on the statistical value of the water intake demand in the area and the formation parameters, oil well parameters and pressure values.

5. The EGS geothermal vertical well-horizontal well development method according to claim 1, characterized in that: Deploying vertical wells within the optimal utilization length of the abandoned horizontal wells includes: The diameter is deployed at the toe portion of the range of optimally utilized length of the abandoned horizontal well.

6. The EGS geothermal vertical well-horizontal well development method according to claim 1, characterized in that: The indoor physical simulation geothermal development division stages include five stages: fluid replacement period, geothermal utilization steep decline period, geothermal utilization slow decline period, geothermal utilization stable period, and geothermal exhaustion period.

7. The EGS geothermal vertical well-horizontal well development method according to claim 6, characterized in that: Based on indoor physical simulation, geothermal development is divided into stages to optimize the stage parameters in the heat exchange process, including: During the fluid replacement period, the vertical well water intake is calculated based on the relationship between the fluid temperature and the formation temperature; During the steep decline period, slow decline period and stable period of geothermal utilization, vertical well water extraction and horizontal well recharge development are carried out based on the U-shaped well development mode, and the vertical well water extraction volume is adjusted based on the different requirements of heat exchange power in different periods; During the geothermal depletion period, water withdrawal is zero.

8. The EGS geothermal vertical well-horizontal well development method according to claim 7, characterized in that: The calculation formula for the vertical well water intake during the fluid replacement period is: Where a is the formation length, m; h is the formation thickness, m; K is the formation permeability, D; L is the horizontal section length, m; P e , supply boundary pressure, MPa; P wf , bottom hole pressure, MPa; q, production (underground), m 3 / ks; R, total seepage resistance of horizontal well, mPa·s / (D·m); r w , oil well radius, m; μ, fluid viscosity, mPa·s.

9. The EGS geothermal vertical well-horizontal well development method according to claim 2, characterized in that: The stratum section includes four sections, the first section is -2000 to -3000m, the second section is -3000 to -3500m, the third section is -3500 to -4000m, and the fourth section is below -4000m.

10. An EGS geothermal vertical well-horizontal well development device, characterized in that: include: A selection module, the selection module is configured to select abandoned horizontal wells; A first optimization module, the first optimization module is configured to determine the optimal utilization length of the abandoned horizontal well based on the regional water intake demand statistics; A simulation deployment module, wherein the simulation deployment module is configured to deploy vertical wells within the optimal utilization length of the abandoned horizontal wells to form a vertical well water extraction and horizontal well recharging well network; The second optimization module is configured to divide the geothermal development into stages based on indoor physical simulation, optimize the stage parameters in the heat exchange process, and calculate the vertical well water intake in different stages.

11. The EGS geothermal vertical well-horizontal well development device according to claim 10, characterized in that: The selection module is further configured to: obtain exploration data of buried hill thermal reservoirs, and select abandoned horizontal wells based on the exploration data.

12. The EGS geothermal vertical well-horizontal well development device according to claim 11, characterized in that: The exploration data include: reservoir burial depth, formation temperature in the middle of the reservoir, formation intervals, number of horizontal wells, water breakthrough depth and water breakthrough formation temperature.

13. The EGS geothermal vertical well-horizontal well development device according to claim 11, characterized in that: The stratum section includes four sections, the first section is -2000 to -3000m, the second section is -3000 to -3500m, the third section is -3500 to -4000m, and the fourth section is below -4000m.

14. The EGS geothermal vertical well-horizontal well development device according to claim 10, characterized in that: The first optimization module is further configured to: The optimal utilization length of the abandoned horizontal well is determined based on the statistical value of the water intake demand in the area and the formation parameters, oil well parameters and pressure values.

15. The EGS geothermal vertical well-horizontal well development device according to claim 10, characterized in that: The simulation deployment module is further configured to: The diameter is deployed at the toe portion of the range of optimally utilized length of the abandoned horizontal well.

16. The EGS geothermal vertical well-horizontal well development device according to claim 10, characterized in that: The indoor physical simulation geothermal development division stages include five stages: fluid replacement period, geothermal utilization steep decline period, geothermal utilization slow decline period, geothermal utilization stable period, and geothermal exhaustion period.

17. The EGS geothermal vertical well-horizontal well development method according to claim 16, characterized in that: The second optimization module is further configured to: During the fluid replacement period, the vertical well water intake is calculated based on the relationship between the fluid temperature and the formation temperature; During the steep decline period, slow decline period and stable period of geothermal utilization, vertical well water extraction and horizontal well recharge development are carried out based on the U-shaped well development mode, and the vertical well water extraction volume is adjusted based on the different requirements of heat exchange power in different periods; During the geothermal depletion period, water withdrawal is zero.

18. The EGS geothermal vertical well-horizontal well development device according to claim 17, characterized in that: The calculation formula for the vertical well water intake during the fluid replacement period is: Where a is the formation length, m; h is the formation thickness, m; K is the formation permeability, D; L is the horizontal section length, m; P e , supply boundary pressure, MPa; P wf , bottom hole pressure, MPa; q, production (underground), m 3 / ks; R, total seepage resistance of horizontal well, mPa·s / (D·m); r w , oil well radius, m; μ, fluid viscosity, mPa·s.

19. A computer device, characterized in that: include: at least one processor; as well as A memory storing computer instructions executable on the processor, wherein the instructions, when executed by the processor, implement the steps of the method according to any one of claims 1 to 9.

20. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 9 are implemented.

Images