Energy recovery method and system based on double-layer formation water pressure difference power generation and readable medium

Abstract

The invention belongs to the technical field of underground overpressure energy utilization, and relates to an energy recovery method and system based on double-layer formation water pressure difference power generation and a readable medium. The method comprises the steps that a deep overpressure water body is extracted from a production well, and the pressure value of the deep overpressure water body is reduced by converting energy in the deep overpressure water body into electric energy; the depressurized deep overpressure water body is injected into an injection layer containing the shallow normal-pressure water body; judging whether the pressure of the injection layer is greater than the safety pressure upper limit; if not, the energy of the deep overpressure water body is continuously converted into electric energy until the target pressure for pressure relief is reached; if yes, the safe injection amount of the deep-layer overpressure water body is calculated, and the depressurized deep-layer overpressure water body is injected into the shallow-layer normal-pressure water body according to the safe injection amount. Deep layer fluid pressure energy recovery and shallow layer fluid injection safety regulation and control can be combined, the water yield and the generating capacity can be accurately calculated, and it is ensured that energy recovery maximization is achieved under absolutely-safe injection pressure.

Description

TECHNICAL FIELD

[0001] The present application relates to an energy recovery method, system and readable medium based on double-layer stratum water pressure difference power generation, belonging to the technical field of underground overpressure energy utilization. BACKGROUND

[0002] Energy shortage and climate change are major challenges facing the world, and promoting the transformation of energy structure to clean and low carbon has become an international consensus. In the exploration and development of oil and gas fields, the utilization of geothermal resources and the storage of deep salt water layer, etc. Engineering activities, deep high pressure fluid system is often encountered. The pressure of these fluids is much higher than the pressure required by the surface treatment equipment, and the traditional process must be depressurized by a throttle valve. This depressurization process essentially wastes the huge pressure potential energy contained in the fluid by throttling friction in the form of heat, which not only causes serious energy waste, but also aggravates the erosion and wear of the equipment and increases the operation and maintenance cost.

[0003] In particular, in the oil industry, the treatment of associated stratum water is a great challenge. Many deep water producing layers of oil fields have the characteristics of abnormally high pressure (pressure coefficient > 1.2), and after these high pressure water bodies are produced, they need to be depressurized to normal pressure for reinjection or treatment, and this process contains huge energy recovery potential. Similarly, in the CCUS (carbon capture, utilization and storage) project, when supercritical CO2 is injected into deep salt water layer, the formation pressure will continue to rise, and in order to maintain the safety of the reservoir, part of the stratum water may be produced to control the pressure, and the high pressure water produced also contains considerable pressure energy. The traditional throttling and depressurizing method completely ignores the recovery value of this part of energy.

[0004] For the recovery of fluid pressure energy, there are some pressure difference power generation technologies based on expanders or turbines on the market, which are mainly used for natural gas pipeline pressure difference power generation or industrial excess pressure recovery. However, simply copying these technologies to the field of geological fluid energy recovery has significant shortcomings and limitations: first, the composition of geological fluid is complex, often containing high concentration of salt, hydrogen sulfide and other corrosive substances and solid particles, which puts extremely harsh requirements on the material and sealing performance of the power generation equipment, and the service life and reliability of general industrial equipment are difficult to guarantee. Secondly, and most importantly, existing technologies only focus on energy recovery itself, but seriously ignore the safety of the underground reservoir closely related to it. Drawing a large amount of fluid from one layer and injecting it into another layer will significantly change the original stratum pressure field, and if the design or control is not proper, it may lead to pressure overrun of the injection layer, causing stratum rupture, loss of sealing performance of the cap rock, even inducing microseismic and other geological disasters, with high environmental risk. Therefore, energy recovery must be carried out on the premise of ensuring the safety and stability of the entire underground system. SUMMARY

[0005] In view of the above problems, the present application aims to provide an energy recovery method, system and readable medium based on double-layer stratum water pressure difference power generation, which can systematically combine deep fluid pressure energy recovery and shallow fluid injection safety control, accurately calculate the recoverable water volume and power generation by coupling the compressibility of two geological bodies, and ensure the maximization of energy recovery under the absolute safe injection pressure.

[0006] To achieve the above object, the present application provides the following technical scheme: an energy recovery method based on double-layer stratum water pressure difference power generation, comprising the following steps: recovering deep overpressure water body from a production well, converting the energy of the deep overpressure water body into electric energy to reduce the pressure value of the deep overpressure water body; injecting the deep overpressure water body after pressure reduction into an injection layer containing shallow normal pressure water body; judging whether the pressure of the injection layer is greater than the upper limit of safe pressure; if not, continuously converting the energy of the deep overpressure water body into electric energy until the target pressure relief pressure is reached; if yes, calculating the safe injection volume of the deep overpressure water body, and injecting the deep overpressure water body after pressure reduction into the shallow normal pressure water body according to the safe injection volume.

[0007] Further, the calculation formula of the target pressure relief pressure is:

[0008] wherein, is the target pressure relief pressure, is the fluid density, is the gravitational acceleration, is the average burial depth of the top surface of the overpressure layer; the total water volume of the deep overpressure water body injected into the injection layer is:

[0009] wherein, is the total water volume of the deep overpressure water body injected into the injection layer, is the comprehensive compression coefficient of the overpressure layer, is the total volume of the water body of the overpressure layer; is the initial pressure of the overpressure layer.

[0010] Further, the final pressure of the injection layer is:

[0011] wherein, is the final pressure of the injection layer, is the initial pressure of the injection layer, is the comprehensive compression coefficient of the injection layer, is the total volume of the water body of the initial injection layer.

[0012] Further, the final pressure of the injection layer is not greater than the upper limit of the safety pressure, and the total amount of electric energy obtained by energy conversion is:

[0013]

[0014] wherein, is the total amount of electric energy when the final pressure of the injection layer is not greater than the upper limit of the safety pressure, is the first average effective pressure difference, is the total efficiency of the system power generation.

[0015] Further, the calculation formula of the safety injection amount is:

[0016] wherein, is the safety injection amount, is the initial pressure of the injection layer, is the comprehensive compression coefficient of the injection layer, is the total volume of the water body in the initial injection layer, is the upper limit of the safety pressure of the injection layer.

[0017] Further, the residual pressure of the overpressure layer containing the deep overpressure water body is:

[0018] wherein, is the residual pressure of the overpressure layer, is the comprehensive compression coefficient of the overpressure layer, is the total volume of the water body in the overpressure layer; is the initial pressure of the overpressure layer.

[0019] Further, the final pressure of the injection layer is greater than the upper limit of the safety pressure, and the total amount of electric energy obtained by energy conversion is:

[0020]

[0021] wherein, the total amount of electric energy when the final pressure of the injection layer is greater than the upper limit of the safety pressure, is the second average effective pressure difference, is the total efficiency of the system power generation.

[0022] Further, the method for converting the energy in the deep overpressure water body into electric energy is: converting the energy in the deep overpressure water body into electric energy by driving the turbine generator set to generate electricity.

[0023] The application further discloses an energy recovery system based on double-layer stratum water pressure difference power generation, comprising: a deep overpressure water body pressure reduction module, which is used for extracting deep overpressure water body from a production well, reducing the pressure value of the deep overpressure water body by converting the energy of the deep overpressure water body into electric energy, a deep overpressure water body injection module, which is used for injecting the deep overpressure water body after pressure reduction into an injection layer containing shallow normal pressure water body, a safety pressure judgment module, which is used for judging whether the pressure of the injection layer is greater than the upper limit of safety pressure, a first pressure relief module, which is used for continuously converting the energy of the deep overpressure water body into electric energy until reaching a pressure relief target pressure, and a second pressure relief module, which is used for calculating a safe injection amount of the deep overpressure water body and injecting the deep overpressure water body after pressure reduction into the shallow normal pressure water body according to the safe injection amount.

[0024] The application further discloses a computer readable storage medium, wherein a computer program is stored on the computer readable storage medium, and the computer program is executed by a processor to implement the energy recovery method based on double-layer stratum water pressure difference power generation.

[0025] The technical scheme of the application has at least the following technical effects or advantages: the application can systematically combine deep fluid pressure energy recovery and shallow fluid injection safety regulation and control, accurately calculate recoverable water amount and power generation amount by coupling the compressibility of two geological bodies, and ensure that the maximum energy recovery is realized under the absolute safe injection pressure; the application can accurately calculate the recoverable pressure energy resource amount under specific geological conditions, and comprises a complete process of pressure monitoring, dynamic regulation and control and power generation system, so that the shallow injection pressure is always controlled within the safe range in the whole 'extraction-power generation-injection' process, and the unification of safety and benefit is realized. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a flow chart of the energy recovery method based on double-layer stratum water pressure difference power generation in an embodiment of the application; Figure 2 is a principle schematic diagram of the energy recovery method based on double-layer stratum water pressure difference power generation in an embodiment of the application. DETAILED DESCRIPTION

[0027] In order for those skilled in the art to better understand the technical scheme of the application, the application is described in detail through specific embodiments. However, it should be understood that the specific embodiments are provided only for better understanding of the application, and they should not be understood as limiting the application. In the description of the application, it should be understood that the terms used are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0028] In order to solve the problem that only the energy recovery itself is concerned in the prior art, and the safety problem of the underground reservoir closely related to the energy recovery is seriously ignored, the present application provides an energy recovery method, system and readable medium based on water pressure difference of double-layer strata, which comprises the following steps: deep overpressure water body is produced from a production well, the pressure value of the deep overpressure water body is reduced by converting the energy in the deep overpressure water body into electric energy; the deep overpressure water body after pressure reduction is injected into an injection layer containing shallow normal pressure water body; it is judged whether the pressure of the injection layer is greater than the upper limit of the safety pressure; if not, the energy in the deep overpressure water body is continuously converted into electric energy until the target pressure of pressure relief is reached; if yes, the safe injection amount of the deep overpressure water body is calculated, and the deep overpressure water body after pressure reduction is injected into the shallow normal pressure water body according to the safe injection amount. The present application can systematically combine the deep fluid pressure energy recovery and the safety regulation of shallow fluid injection, accurately calculate the recoverable water amount and the power generation amount by coupling the compressibility of the two geological bodies, and ensure that the energy recovery is maximized under the absolute safe injection pressure, thereby providing key technical support for the efficient and safe development of geopressure energy. The present application will be described in detail below with reference to the accompanying drawings.

[0029] Embodiment one In the process of oil and gas exploitation and geothermal development, high pressure or even overpressure strata are often encountered. The traditional method is to reduce the pressure of high pressure fluid to the pressure required by the treatment equipment through a throttle valve, which wastes a lot of pressure energy. On the other hand, when water is injected into the strata (such as aquifer), a large amount of electric energy is consumed to drive the water pump to increase the injection pressure. The energy recovery method in the present embodiment aims to solve the above two problems, i.e. to recover the discharged energy and to realize low pressure injection.

[0030] The present embodiment discloses an energy recovery method based on water pressure difference of double-layer strata, which is characterized in that the deep overpressure water body is used as a power source to drive a generator set, and the fluid after power generation is safely injected into the shallow aquifer. As shown in Figure 1 , the method comprises the following steps: S1 deep overpressure water body is produced from a production well, and the pressure value of the deep overpressure water body is reduced by converting the energy in the deep overpressure water body into electric energy.

[0031] In the present embodiment, the method for converting the energy in the deep overpressure water body into electric energy is to drive a turbine generator set to convert the energy in the deep overpressure water body into electric energy and generate power. As shown in Figure 2 , the hardware system for energy recovery comprises a deep production well, a turbine generator set, a shallow injection well and a pressure monitoring system. The deep overpressure water body (initial pressure P1, volume V1) is produced from the production well, drives the turbine generator set to work and generate power, and after the pressure is reduced to a value slightly higher than the instantaneous pressure of the shallow layer, the deep overpressure water body is injected into the shallow normal pressure water body (initial pressure P2, volume V2). The strata containing the deep overpressure water body are referred to as overpressure layer, and the strata containing the shallow normal pressure water body are referred to as injection layer.

[0032] S2 injects depressurized deep overpressured water into the injection layer containing shallow normal-pressured water.

[0033] S3 determines whether the pressure of the injection layer is greater than the upper limit of the safe pressure.

[0034] This step is a safety verification step. If the pressure in the injection layer exceeds the upper limit of the safe pressure, there may be a safety hazard, so injection into the deep overpressured water body cannot continue. That is, the overpressured layer has not yet been depressurized to the depressurization target pressure P10, but the shallow injection pressure has risen to the upper limit of the safety P20. At this time, injection must be stopped, and the power generation process is terminated prematurely.

[0035] The formula for calculating the target pressure for pressure relief is:

[0036] in, This is the target pressure for pressure relief, measured in Pa. It is set to the static water pressure at the same depth, with the target pressure being the static water column pressure, meaning the pressure coefficient is reduced to 1.0. This refers to the fluid density, expressed in kg / m³. In this example, the fluid is water, with a density of 1000 kg / m³. It is the acceleration due to gravity, taken as 9.8 m / s². It is the average burial depth of the top surface of the overpressure layer, in meters. In this embodiment... =3000m.

[0037] The unit of the upper limit of the safe pressure of the injection layer, P20, is Pa. It is usually taken to be slightly lower than the formation fracturing pressure. In this embodiment, the upper limit of the safe pressure of the injection layer, P20, is a given value, that is, P20 = 13 MPa.

[0038] If S4 is not the case, the energy of the deep overpressured water body will continue to be converted into electrical energy until the pressure relief target is reached.

[0039] The total volume of water injected into the injection layer from deep overpressured water bodies is determined by the pressure drop and compressibility of the overpressured layer containing the deep overpressured water body, and the calculation formula is as follows:

[0040] in, It is the total volume of deep, overpressured water injected into the injection layer. It is the overall compressibility coefficient of the overpressure layer, with units of Pa. - ¹, In this embodiment It is 1.0×10 -9 Pa -1 . =(1.0×10 -9 )*(8.0×10 9 )* (52.92e6 -30.0e 6 = 8.0 * 22.92e 6 = 183,360,000 m³ It is the total volume of the overpressure layer water, expressed in m³, and its calculation formula is:

[0041] in, This is the average thickness of the overpressure layer, in meters (m). It is the area of ​​the overpressure layer, in m². The porosity of the overpressure layer; in this embodiment =400m, =100 km², =0.20. V1=1×10 8 *400* 0.20=8,000,000,000m³=8.0×10 9 m³.

[0042] This is the pressure of the initial overpressure layer, expressed in Pa, and its calculation formula is:

[0043] in, It is the average pressure coefficient at depth of the overpressure layer, which is dimensionless. The above formula calculates the maximum theoretical water volume that can be extracted from the overpressure zone due to the pressure drop. In this embodiment... =1.8. P1=1000* 9.8*3000* 1.8=52,920,000Pa=52.92MPa.

[0044] injection After the water volume is increased, the pressure in the injection layer will rise. The maximum pressure is determined by the compressibility of the injection layer. The formula for calculating the final pressure of the injection layer is:

[0045] in, It is the final pressure of the injection layer. This is the pressure of the initial injection layer, measured in Pa, and its calculation formula is:

[0046] in, It is the average burial depth pressure coefficient of the injection layer, which is dimensionless. . It is the average burial depth of the top surface of the injection layer, in meters. In this embodiment... = 1.0, = 1000 m. = 1000 * 9.8 * 1000 * 1.0 = 9.8 MPa. is the comprehensive compression coefficient of the normal pressure layer, with the unit of Pa - , in the embodiment is 1.0 * 10 -9 Pa -1 , is the total volume of the water in the initial injection layer, with the unit of m³, and the calculation formula is as follows:

[0047] wherein, is the average thickness of the injection layer, with the unit of m, is the distribution area of the injection layer, with the unit of m², is the porosity of the injection layer, in the embodiment = 600 m, = 150 km², = 0.25. = 1.5 * 10 8 * 600 * 0.25 = 22,500,000,000 m³ = 2.25 * 10 10 m³. After the total water amount is injected according to the above formula, the equilibrium pressure of the injection layer is reached. In the embodiment, 9.8e 6 + 183.36e 6 / (1.0 * 10 -9 ) * (2.25 * 10 10 ) = 9.8e 6 + 183.36e 6 / 22.5 = 9.8e 6 + 8.149e 6 = 17,949,000 Pa = 17.95 MPa > P20 = 13 MPa. Therefore, it should enter step S5 for calculation.

[0048] The final pressure of the injection layer is not greater than the upper limit of the safety pressure, and the total amount of the electric energy obtained by the energy conversion is:

[0049]

[0050] wherein, is the total amount of the electric energy when the final pressure of the injection layer is not greater than the upper limit of the safety pressure, is the difference between the average pressure of the overpressure layer and the average pressure of the shallow layer, i.e. the first average effective pressure difference, since the pressure difference is continuously attenuated throughout the process, the average pressure method is used for simplified calculation, the result is conservative but applicable to engineering evaluation, is the total power generation efficiency of the system, and its calculation formula is turbine efficiency x generator efficiency, in this embodiment, the empirical value 0.70 is taken, but it is not limited thereto. The total amount of electric energy is joule J, which is equal to the product of the average effective pressure difference, the total discharge amount and the system efficiency. For the convenience of understanding, the final result will be converted into kilowatt hours (kWh).

[0051] S5 if yes, the safe injection amount of the deep overpressure water body is calculated, and the deep overpressure water body after pressure reduction is injected into the shallow normal pressure water body according to the safe injection amount.

[0052] The safe injection amount is determined by the allowable pressure rise of the injection layer and the compressibility of the injection layer, and its calculation formula is:

[0053] wherein, is the safe injection amount, is the initial pressure of the injection layer, is the comprehensive compression coefficient of the injection layer, is the total volume of the water body in the initial injection layer, is the upper limit of the safe pressure of the injection layer. The above formula calculates the maximum allowable injection water amount under the premise of ensuring that the shallow layer pressure does not exceed the limit.

[0054] In this embodiment, (1.0×10 -9 )*(2.25×10 10 )* (13e 6 -9.8e 6 ) = 72,000,000m³.

[0055] After the overpressure layer produces the safe injection amount of water, its pressure is reduced, and the amount of reduction is determined by the compressibility of the overpressure layer, and the residual pressure of the overpressure layer is:

[0056] wherein, is the residual pressure of the overpressure layer, is the comprehensive compression coefficient of the overpressure layer, is the total volume of the initial stratum water body; is the initial pressure of the overpressure layer.

[0057] 52.92e 6 -72.0e 6 / (1.0×10 -9 )*(8.0×10 9)=52.92e 6 -72.0e 6 / 8 = 43.92 MPa It is greater than P10 = 30 MPa.

[0058] When the final pressure of the injection layer exceeds the upper limit of the safety pressure, the total electrical energy obtained through energy conversion is:

[0059]

[0060] in, The total electrical energy required when the final pressure of the injection layer exceeds the upper limit of the safe pressure. It is the second average effective pressure difference, which is the difference between the average of the starting and ending pressures of the overpressure layer and the average of the starting and upper limit of the safe pressure P20 of the injection layer. It is the overall power generation efficiency of the system.

[0061] In this embodiment, [(52.92+43.92) / 2-(9.8+13) / 2]= [48.42-11.4]=37.02MPa; =37,020,000Pa*72,000,000m³*0.70= 1.866×10 18 J. 1kWh = 3.6 × 10 6 J.

[0062] =(1.866×10 18 ) / (3.6×10 6 518,333,000 kWh ≈ 518 million kWh Economic and environmental benefits estimation: Sales revenue from electricity generation (calculated at an electricity price of 0.6 yuan / kWh): 518,333,000 kWh * 0.6 yuan / kWh ≈ 311 million yuan; CO2 emission reduction (calculated at a grid emission factor of 0.8 kgCO2 / kWh): 518,333,000 kWh * 0.8 kg / kWh = 414,666,400 kg = 414,666 tons.

[0063] According to the above economic and environmental benefit estimation, although it is not feasible to achieve full pressure relief due to the capacity limitation of the injection layer, through the regulation of safety constraints, up to 518 million kWh of electric energy can still be recovered, generating significant economic benefits (about 311 million yuan) and environmental benefits (about 415,000 tons of CO2 emission reduction). The method of the embodiment prioritizes injection safety while maximizing energy recovery, and has broad application prospects in the fields of deep aquifer energy storage, oilfield associated water treatment, and geothermal development.

[0064] Embodiment Two Based on the same inventive concept, the embodiment discloses an energy recovery system based on double-layer stratum water pressure difference power generation, comprising: a deep overpressure water body pressure reduction module for producing deep overpressure water bodies from production wells, converting the energy of the deep overpressure water bodies into electric energy, and reducing the pressure value of the deep overpressure water bodies; a deep overpressure water body injection module for injecting the deep overpressure water bodies after pressure reduction into an injection layer containing shallow normal pressure water bodies; a safety pressure judgment module for judging whether the pressure of the injection layer is greater than the upper limit of the safety pressure; a first pressure relief module for continuously converting the energy of the deep overpressure water bodies into electric energy until the pressure relief target pressure is reached; a second pressure relief module for calculating the safe injection amount of the deep overpressure water bodies, and injecting the deep overpressure water bodies after pressure reduction into the shallow normal pressure water bodies according to the safe injection amount.

[0065] Embodiment Three Based on the same inventive concept, the embodiment discloses a computer readable storage medium, the computer readable storage medium has a computer program stored thereon, and the computer program is executed by a processor to implement the energy recovery method based on double-layer stratum water pressure difference power generation of any one of the above embodiments.

[0066] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

[0067] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.

[0068] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.

[0069] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.

[0070] Finally, it should be noted that the above-mentioned embodiments are merely intended to illustrate the technical solutions of the present application, rather than limit the same. Although the present application is described in detail with reference to the above embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or equivalent replacements without departing from the spirit and scope of the present application, and any modifications or equivalent replacements shall be included in the protection scope of the present application. The above content is merely a specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which shall be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An energy recovery method based on double-layer ground water pressure difference power generation, characterized in that, Includes the following steps: Deep overpressure water is extracted from production wells, and its energy is converted into electrical energy to reduce the pressure value of the deep overpressure water. Deep, overpressured water that has been depressurized is injected into an injection layer containing shallow, normal-pressure water. Determine whether the pressure of the injection layer is greater than the upper limit of the safe pressure; If not, the energy of the deep overpressured water body will continue to be converted into electrical energy until the pressure relief target is reached; If so, calculate the safe injection volume of the deep overpressure water body, and inject the depressurized deep overpressure water body into the shallow normal pressure water body according to the safe injection volume.

2. The energy recovery method based on double-layer ground water pressure difference power generation as described in claim 1, characterized in that, The formula for calculating the pressure relief target is: in, It is the target pressure for pressure relief. It is fluid density. It is gravitational acceleration. It is the average burial depth of the top surface of the overpressure layer; The total volume of deep, overpressured water injected into the injection layer is: in, It is the total volume of deep, overpressured water injected into the injection layer. It is the overall compressibility coefficient of the overpressure layer. It is the total volume of water in the overpressure layer; It is the pressure of the initial overpressure layer.

3. The energy recovery method based on double-layer formation water pressure difference power generation as described in claim 2, characterized in that, The final pressure of the injection layer is: in, It is the final pressure of the injection layer. It is the pressure of the initial injection layer. It is the overall compression coefficient of the injection layer. It is the total volume of water in the initial injection layer.

4. The energy recovery method based on double-layer formation water pressure difference power generation as described in claim 3, characterized in that, The final pressure of the injection layer does not exceed the upper limit of the safety pressure, and the total electrical energy obtained from energy conversion is: in, It is the total electrical energy when the final pressure of the injection layer does not exceed the upper limit of the safe pressure. It is the first average effective pressure difference. It is the overall power generation efficiency of the system.

5. The energy recovery method based on double-layer formation water pressure difference power generation as described in claim 1, characterized in that, The formula for calculating the safe injection amount is: in, This is the safe injection volume. It is the pressure of the initial injection layer. It is the overall compression coefficient of the injection layer. It is the total volume of water in the initial injection layer. It is the upper limit of the safe pressure of the injection layer.

6. The energy recovery method based on double-layer formation water pressure difference power generation as described in claim 5, characterized in that, The residual pressure of the overpressure layer, which includes deep overpressured water bodies, is: in, It is the residual pressure of the overpressure layer. It is the overall compressibility coefficient of the overpressure layer. It is the total volume of water in the overpressure layer; It is the pressure of the initial overpressure layer.

7. The energy recovery method based on double-layer formation water pressure difference power generation as described in claim 6, characterized in that, When the final pressure of the injection layer exceeds the upper limit of the safety pressure, the total electrical energy obtained through energy conversion is: in, The total electrical energy required when the final pressure of the injection layer exceeds the upper limit of the safe pressure. It is the second average effective pressure difference. It is the overall power generation efficiency of the system.

8. The energy recovery method based on double-layer formation water pressure difference power generation as described in any one of claims 1-7, characterized in that, The method for converting energy in deep, overpressured water bodies into electrical energy is as follows: by driving a turbine generator set, the energy in the deep, overpressured water bodies is converted into electrical energy to generate electricity.

9. An energy recovery system based on the pressure difference of two-layer ground water for power generation, characterized in that, include: A deep overpressure water body depressurization module is used to extract deep overpressure water from production wells and reduce the pressure value of the deep overpressure water body by converting the energy therein into electrical energy. The deep overpressure water injection module is used to inject depressurized deep overpressure water into an injection layer containing shallow normal-pressure water. The safety pressure determination module is used to determine whether the pressure of the injection layer is greater than the upper limit of the safety pressure. The first pressure relief module is used to continuously convert the energy of deep overpressured water into electrical energy until the target pressure for pressure relief is reached. The second pressure relief module is used to calculate the safe injection volume of the deep overpressure water body, and inject the depressurized deep overpressure water body into the shallow normal pressure water body according to the safe injection volume.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which is executed by a processor to implement the energy recovery method for power generation based on the pressure difference between two layers of ground water as described in any one of claims 1-8.

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