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CN-121993907-A - Method for storing energy and releasing energy and obtaining geothermal energy through stratum cracks of non-communicated well bore

CN121993907ACN 121993907 ACN121993907 ACN 121993907ACN-121993907-A

Abstract

The invention discloses a method for storing energy and releasing energy and obtaining geothermal energy through stratum cracks of a non-communicated shaft, which comprises the steps of identifying an energy storage geothermal layer which contains geothermal resources and does not contain oil gas, injecting high-pressure fluid into a target shaft in the energy storage geothermal layer to enable target artificial stratum cracks to be generated or opening target original stratum cracks in the target shaft in a closed state, injecting normal-temperature high-pressure fluid into the target shaft to enable the width of stratum cracks to be increased, so that stratum rocks are subjected to elastic deformation energy storage, and fluid in the stratum cracks is subjected to heat exchange with the energy storage geothermal layer, closing a reverse drainage pipeline to enable the fluid to continuously undergo heat exchange with the energy storage geothermal layer to enable the fluid to be subjected to heat storage, and driving a hydroelectric power generation device and a geothermal power generation device to generate power by utilizing the high-temperature high-pressure fluid reversely discharged in the closing process of the stratum cracks, so that the obtained geothermal energy and the stratum rock elastic deformation energy are converted into electric energy to be released.

Inventors

  • WANG HANYI
  • HU ZHIWEN

Assignees

  • 绍兴远西能源科技有限公司

Dates

Publication Date
20260508
Application Date
20250530
Priority Date
20240605

Claims (10)

  1. 1. A method of storing and releasing energy and capturing geothermal energy through a formation fracture in a non-communicating wellbore, comprising: Identifying an energy storage geothermal layer containing geothermal resources and free of oil and gas; Injecting high-pressure fluid into a target well bore in the energy storage geothermal layer, so that the energy storage geothermal layer generates at least one target artificial stratum fracture, or opening at least one target original stratum fracture in a closed state in the target well bore in the energy storage geothermal layer, wherein the target well bore is not communicated with any other well bore through the stratum fracture; Injecting normal-temperature high-pressure fluid into the target shaft, so that the width of the target artificial stratum fracture or the target original stratum fracture in the target shaft is increased, the expansion radius is kept unchanged or constant, and therefore stratum rock is elastically deformed to store energy, and the fluid in the target artificial stratum fracture or the target original stratum fracture is subjected to heat exchange with an energy storage geothermal layer to increase the temperature of the fluid; When the width of at least one target artificial stratum crack or at least one target original stratum crack in the target shaft reaches a target width, closing a reverse drainage pipeline to enable fluid in the stratum crack and the energy storage geothermal layer to continuously generate heat exchange so that the temperature of the fluid is continuously increased, and carrying out heat storage; Driving a preset hydroelectric power generation device and a geothermal power generation device to generate power by utilizing high-temperature and high-pressure fluid reversely discharged in the process of closing the target artificial stratum fracture or the target original stratum fracture, so that the obtained geothermal energy and the stratum rock elastic deformation energy are converted into electric energy for energy release; And driving a preset hydroelectric power generation device and a geothermal power generation device to generate power by utilizing the reverse-discharged high-temperature and high-pressure fluid in the target artificial stratum fracture or the target original stratum fracture closing process, so as to convert the obtained geothermal energy and the stratum rock elastic deformation energy into electric energy for energy release, wherein the method specifically comprises the following steps of: Under the condition of power generation requirement, driving hydroelectric power generation equipment to generate power by using fluid reversely discharged in the closing process of target formation cracks, wherein the target formation cracks comprise the target artificial formation cracks or the target original formation cracks; And/or when the heat storage time length of the target shaft is greater than or equal to the pre-calculated target closed heat storage time length, driving geothermal power generation equipment by using fluid to generate power; and/or judging whether the fluid temperature reaches the heating requirement or not under the condition that the heating requirement exists, and using the fluid for heating under the condition that the fluid temperature reaches the heating requirement.
  2. 2. A method of storing and releasing energy and capturing geothermal energy through a fracture in a subterranean formation in a non-communicating wellbore according to claim 1, further comprising the steps of: Injecting high-pressure fluid into the target shaft, so that the actual three-dimensional size of the target artificial stratum fracture in the target shaft is monitored in real time in the process of generating at least one target artificial stratum fracture by the energy storage geothermal layer; Judging whether the actual three-dimensional size reaches a preset threshold value or not, and stopping injecting high-pressure fluid into the target shaft when the actual three-dimensional size reaches the preset threshold value through real-time monitoring, so as to ensure that the target shaft is not communicated with other adjacent shafts through target artificial stratum cracks, wherein the preset threshold value is the minimum value of the preset energy storage three-dimensional size and the preset safety three-dimensional size.
  3. 3. A method of storing and releasing energy and capturing geothermal energy through a fracture of a subterranean formation in a non-communicating wellbore according to claim 2, wherein the actual three-dimensional dimensions comprise an actual radius of expansion and/or an actual height of expansion, the step of configuring the predetermined threshold comprising the steps of: Acquiring a distance L 0 between the target well bore and a nearest neighboring well bore and an actual expansion radius R Adjacent to or an actual expansion height H Adjacent to of stratum cracks in the nearest neighboring well bore; Determining a safe propagation radius R 0 of the target synthetic formation fracture in the target wellbore based on the spacing L 0 and an actual propagation radius R Adjacent to of the formation fracture in a nearest neighbor wellbore, the safe propagation radius R 0 satisfying the condition R 0 ＜L 0 -R Adjacent to ; Judging whether a preset target expansion radius R 0 'of the target artificial stratum fracture is larger than or equal to a preset safety expansion radius R 0 , taking the safety expansion radius R 0 as a set threshold value of the target artificial stratum fracture in the target shaft if the target expansion radius R 0 ' is larger than or equal to the safety expansion radius R 0 , and taking the target expansion radius R 0 'as the set threshold value of the target artificial stratum fracture in the target shaft if the target expansion radius R 0 ' is smaller than the safety expansion radius R 0 ; Or alternatively Acquiring a height difference V 0 between the starting point of the target artificial formation fracture and the starting point of the nearest formation fracture on the nearest neighboring well shaft, and an actual expansion height H Adjacent to of the nearest formation fracture on the nearest neighboring well shaft; Determining a safe extension height H 0 of a target artificial formation fracture in the target wellbore based on the height difference V 0 and an actual extension height H Adjacent to of a nearest formation fracture on the nearest neighbor wellbore, the safe extension height H 0 satisfying the condition H 0 ＜V 0 -H Adjacent to ; Judging whether a preset target expansion height H 0 ' of the target artificial stratum fracture is larger than or equal to a preset safety expansion height H 0 , taking the safety expansion height H 0 as a set threshold value of the target stratum fracture in the target well bore if the target expansion height H 0 ' is larger than or equal to the safety expansion height H 0 , and taking the target expansion height H 0 as the set threshold value of the target stratum fracture in the target well bore if the target expansion height H 0 ' is smaller than the safety expansion height H 0 .
  4. 4. A method of storing and releasing energy and capturing geothermal energy from a formation fracture in a non-communicating wellbore according to claim 3, wherein if the safe expansion radius R 0 is taken as the set threshold for the target formation fracture in the target wellbore, the step of injecting high pressure fluid into the target wellbore such that the geothermal energy storage layer creates at least one target artificial formation fracture comprises: Recalculating the target expansion height of the target formation fracture based on a preset target energy storage amount and the safety expansion radius R 0 ; Adjusting construction parameters according to the recalculated target expansion height and the safety expansion radius R 0 , so that the final actual expansion radius of the target stratum fracture is smaller than or equal to the safety expansion radius, and the final actual expansion height is larger than or equal to the recalculated target expansion height; Or alternatively If the safety expansion height H 0 is used as the set threshold value of the target formation fracture in the target wellbore, injecting high-pressure fluid into the target wellbore, so that the step of generating at least one target artificial formation fracture by the energy storage geothermal layer specifically comprises: re-calculating the target expansion radius of the target stratum fracture based on a preset target energy storage amount and the safety expansion height H 0 ; And adjusting construction parameters according to the recalculated target expansion radius and the safety expansion height H 0 , so that the final actual expansion radius of the target stratum fracture is larger than or equal to the recalculated target expansion radius, and the final actual expansion height is smaller than or equal to the safety expansion height.
  5. 5. The method of storing and releasing energy and capturing geothermal energy through a fracture in a subterranean formation in a non-communicating wellbore of claim 1, further comprising: If the target shaft has a plurality of power generation requirements, judging whether the outlet temperature of the target shaft meets the requirements of geothermal power generation equipment or not; If the outlet temperature of the target shaft does not reach the requirement of geothermal power generation equipment, the reverse drainage fluid of the target shaft is randomly selected to generate power, and when the outlet temperature of any target shaft reaches the requirement of geothermal power generation equipment, the reverse drainage fluid of any target shaft is utilized to cooperatively generate power; the method for judging whether the outlet temperature of the shaft meets the requirement of geothermal power generation equipment comprises the following steps: simulating the change relation between the closed heat storage time length of the shaft and the outlet temperature of the shaft based on a fluid-solid thermal coupling numerical model; calculating the required closed heat storage duration by using a fluid-solid thermal coupling numerical model according to the shaft outlet temperature required by the power generation or/and heating requirements; if the closed heat storage duration is up, the temperature of the shaft outlet reaches the requirement of geothermal power generation equipment.
  6. 6. A method of storing and releasing energy and capturing geothermal energy through a fracture in a subterranean formation in a non-communicating wellbore according to claim 1, further comprising the steps of: Before fluid is discharged, a minimum volume threshold value of high-temperature and high-pressure fluid to be reserved in the target artificial stratum fracture or the target original stratum fracture is calculated and obtained in advance based on preset energy storage cycle efficiency and a hydraulic fracturing model when energy release of the target artificial stratum fracture or the target original stratum fracture is finished, And controlling the reverse discharge process of the high-temperature high-pressure fluid in the target artificial stratum fracture or the target original stratum fracture based on the minimum volume threshold value, so that when energy release is finished, the volume of the high-temperature high-pressure fluid reserved in the target artificial stratum fracture or the target original stratum fracture is larger than or equal to the minimum volume threshold value, and the fracture width of the stratum fracture in energy storage and energy release circulation is ensured to be larger than or equal to a preset width threshold value.
  7. 7. A method of storing and releasing energy and capturing geothermal energy through a fracture in a subterranean formation in a non-communicating wellbore according to claim 3, further comprising the steps of: Determining whether the distance between the target well bore and at least one nearest neighbor well bore is less than or equal to a preset distance threshold, or whether the height difference between the initiation point of the target artificial formation fracture or the target original formation fracture in the target well bore and the nearest formation fracture initiation point on the nearest neighbor well bore is less than or equal to a preset height difference threshold, If so, monitoring whether formation cracks between adjacent shafts are communicated in real time in the energy storage process, and if so, injecting high-pressure fluid into all the communicated shafts simultaneously when the communicated target shafts and the adjacent shafts are used for storing energy, and reversely discharging the high-pressure fluid through all the communicated shafts simultaneously when energy is released, and converting kinetic energy of the high-pressure fluid and acquired heat energy into electric energy.
  8. 8. The method for storing and releasing energy and obtaining geothermal energy through formation fractures of a non-communicating wellbore of claim 1, wherein said step of injecting a high pressure fluid into a target wellbore in said geothermal energy storage layer and opening at least one target virgin formation fracture in said geothermal energy storage layer comprises the steps of identifying at least one virgin formation fracture in said geothermal energy storage layer and screening at least one virgin formation fracture in a closed state from said at least one virgin formation fracture and screening at least one target virgin formation fracture therefrom; Wherein, the step of screening at least one target original stratum fracture from the target original stratum fracture specifically comprises the following steps: the original stratum fracture comprises an original artificial fracture in a closed state, and the step of screening at least one target stratum fracture from the original artificial fracture comprises the following steps: Acquiring first monitoring data of an original artificial crack in the energy storage geothermal layer by using preset monitoring equipment; Calculating the original length and the original height of the original artificial crack in the energy storage geothermal layer by combining the first monitoring data with the first construction parameters of the original artificial crack obtained in advance through a crack expansion numerical model; Judging whether the original length and the original height of the original artificial fracture reach a preset target length threshold value and a preset target height threshold value, if so, marking the original artificial fracture as the target original stratum fracture, and/or, The original stratum fracture comprises a natural fracture in a closed state, and the step of screening at least one target original stratum fracture from the natural fracture comprises the following steps: Acquiring second monitoring data of the natural cracks in the energy storage geothermal layer through preset monitoring equipment, and inverting according to the second monitoring data to obtain distribution of the at least one natural crack, wherein the second monitoring data comprises logging data and seismic data; obtaining three-dimensional stress distribution of the energy storage geothermal layer through structural stress analysis; by means of three-dimensional slits The stress coupling model simulates the opening of the at least one natural crack in the process of injecting normal-temperature high-pressure fluid into the at least one natural crack, and calculates energy storage energy when the width of the at least one natural crack is expanded to a target width under the action of the normal-temperature high-pressure fluid; And judging whether the stored energy reaches a preset target stored energy, if so, marking the at least one natural fracture as a target original stratum fracture.
  9. 9. The method of claim 8, wherein determining whether the number of screened target original formation fractures reaches a predetermined number threshold, and if not, secondarily reforming the original artificial fractures whose original length and original height do not reach a predetermined target length threshold and a predetermined target height threshold, and/or reforming the natural fractures whose original length and original height do not reach a predetermined target length threshold and a predetermined target height threshold; the secondary reconstruction of the original artificial crack comprises the following steps: Injecting fluid into the original stratum fracture through a shaft according to preset third construction parameters, so that the fracture pressure in the original stratum fracture is larger than the fracture expansion pressure, and the original stratum fracture is expanded along the original height direction and the original length direction of the original stratum fracture; acquiring third monitoring data in the original stratum crack expansion process through monitoring equipment; Calculating the latest length and the latest height of the original stratum fracture after the original stratum fracture extends along the original height and the original length according to the third construction parameters and the third monitoring data by combining a fracture expansion numerical model; judging whether the latest length and the latest height reach a preset target length threshold value and a preset target height threshold value, if so, stopping injecting the high-pressure fluid to obtain the target original stratum fracture; The step of reforming the natural fracture specifically comprises the following steps: Injecting fluid into the natural fracture through a shaft according to preset fourth construction parameters, so that the fracture pressure in the natural fracture is larger than the fracture expansion pressure, and the natural fracture is expanded along the original height and original length directions; acquiring fourth monitoring data in the natural crack expansion process through the monitoring equipment; Calculating the latest length and the latest height of the natural cracks after extension by using a crack extension numerical model according to the fourth construction parameters and the fourth monitoring data; And judging whether the latest length and the latest height of the delayed natural fracture reach a preset target length threshold value and a preset target height threshold value, if so, stopping injecting fluid to obtain the target original stratum fracture.
  10. 10. The method for storing and releasing energy and obtaining geothermal energy through formation fractures of a non-communicating wellbore according to claim 9, wherein during the secondary modification of the original artificial fracture or the modification of the natural fracture, the actual three-dimensional size of the original artificial fracture or the natural fracture is monitored in real time, whether the actual three-dimensional size reaches a preset threshold value is judged, and when the actual three-dimensional size reaches the preset threshold value by real-time monitoring, high-pressure fluid injection into the wellbore is stopped, so that the target wellbore is ensured not to communicate with other adjacent wellbores through the modified artificial formation fracture or the natural formation fracture.

Description

Method for storing energy and releasing energy and obtaining geothermal energy through stratum cracks of non-communicated well bore Priority application The application claims priority of China patent application No. 2024107219672 filed in 6 month 5 2024, which is a method and a system for storing and releasing energy and acquiring geothermal energy through formation cracks, and No. 2024112086187, which is a method and a system for storing and releasing energy and acquiring geothermal energy through original formation cracks of a stratum, and the two priority patent applications are incorporated by reference in their entirety. Technical Field The invention relates to the field of underground energy storage, in particular to a method for storing and releasing energy through stratum cracks and obtaining geothermal energy. Background Renewable energy sources such as wind energy, solar energy, and the like often have significant intermittent, fluctuating, random characteristics. With large-scale development of new energy and high-proportion grid connection, electric power and electricity balance, safety and stability control and the like face unprecedented challenges. Therefore, the energy storage industry balances the fluctuation of new energy power generation and meets the necessary requirement of peak demand of the power utilization end. The prior energy storage technology mainly comprises mechanical energy storage and electrochemical energy storage. The electrochemical energy storage comprises lead-acid batteries, lithium ion batteries, hydrogen fuel battery energy storage and the like. Because of high investment and maintenance cost, and environmental and safety problems, the mechanical energy storage mainly comprises pumping energy storage, air compression energy storage and the like, and is not used in a large scale. The water pumping and energy storage method is to pump water from a lower position to a higher position of the land and convert electric energy into gravitational potential energy of the water, so that the water pumping and energy storage method has high requirements on the land structure, cannot be applied to plain or hilly areas with flat land, and has corresponding requirements on climate and rainfall of application areas, and the compressed air energy storage is a mature energy storage technology, but waste mines or underground caves are required to be used as air storage media, so that the water pumping and energy storage method can only be used in certain specific areas. Geothermal energy is also the main direction of new energy development at present. The exploitation of geothermal energy conventionally includes a way that technological paths are completely contradictory, namely, the way of exploiting geothermal energy through hydraulic fracturing is adopted, and the way of exploiting geothermal energy is adopted, wherein the way is adopted for avoiding the generation of cracks in a bottom layer through hydraulic fracturing, and only faults with relatively developed natural cracks in the stratum are adopted as target exploiting geothermal energy. Among them, a method of exploiting geothermal heat by hydraulic fracturing is generally called an enhanced geothermal system, which requires at least two wellbores (one injection fluid, one exploitation fluid) communicating through formation cracks to work cooperatively, and the formation cracks are closed during geothermal exploitation, and the crack gaps are supported only by rough surfaces or proppants. The defects of the method include that the cracks are in a closed state, the gaps of the cracks are small, friction resistance in the cracks is large, so that energy loss of injection fluid is large (parasitic load is large), and because the injection well and the exploitation well are communicated by a plurality of stratum cracks, the injection fluid easily flows through the stratum cracks with large gaps of the cracks rapidly, and heat exchange with surrounding rocks cannot be effectively carried out, so that thermal short circuit is caused, and the temperature of an outlet of the exploitation well is suddenly reduced. For example, the invention patent application with publication number of CN117150591A discloses a multi-well enhanced geothermal system construction method, which comprises (1) drilling an injection well of which a vertical well is a multi-well enhanced geothermal system into a thermal reservoir, simultaneously taking a wellhead as a center and arranging microseism monitoring shallow well stations around the vertical well, (2) carrying out large-scale hydraulic fracturing on the vertical well, carrying out moment tensor inversion on stress waves received by the microseism monitoring shallow well stations to obtain source mechanism information, determining important parameters of a main hydraulic fracture, (3) establishing a continuous fracture network model, displaying the distribution of fracture permeability in the therma