A method and device for determining an energy storage and repeated fracturing mode

Abstract

The present specification provides a method and device for determining an energy accumulation and repeated fracturing mode. The method comprises: performing different modes of energy accumulation and repeated fracturing on a sealed target core sample, the target core sample having initial fracture characteristic data; determining a fracture zone of the target core sample after the different modes of energy accumulation and repeated fracturing and extracting target fracture characteristic data of the fracture zone; determining comprehensive fracture characteristic data according to the initial fracture characteristic data and the target fracture characteristic data, the comprehensive fracture characteristic data being used to determine fracturing effects of the different modes of energy accumulation and repeated fracturing; comparing the comprehensive fracture characteristic data and selecting a target energy accumulation and repeated fracturing mode according to a comparison result. Based on the above method, an optimal energy accumulation and repeated fracturing mode can be selected, guidance can be provided for fracturing sites, and oil well productivity can be improved.

Description

Technical Field

[0001] This specification relates to the field of hydraulic fracturing technology, and in particular to a method and apparatus for determining an energy storage repeated fracturing mode. Background Technology

[0002] Unconventional oil and gas resources have large reserves, but their extraction requires advanced technology and suffer from poor reservoir properties. To obtain industrial oil and gas flow, unconventional oil and gas reservoirs need to be fracturing to improve fluid flow conditions. Since fracturing unconventional oil and gas wells face challenges such as depletion-driven development, severe formation depletion, rapid decline in single-well production, and low recovery rates, repeated fracturing can be used to increase well productivity.

[0003] Existing refractory fracturing methods suffer from the following problems: Firstly, they often employ temporary plugging and redirection refractory fracturing, failing to achieve the goal of energy storage before redirection fracturing, resulting in poor refractory fracturing performance and low well productivity. Secondly, there is a lack of laboratory simulation methods for energy storage refractory fracturing, making it impossible to intuitively evaluate the synergistic relationship between energy storage and temporary plugging, and their impact on fracture propagation and redirection during refractory fracturing. Consequently, it is impossible to select the optimal energy storage refractory fracturing method to provide guidance for fracturing operations and improve well productivity.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] This specification provides a method and apparatus for determining the energy storage repeated fracturing mode, in order to solve the problem that existing technologies cannot accurately and efficiently determine the optimal energy storage repeated fracturing mode, resulting in low oil well productivity.

[0006] On the one hand, the embodiments of this specification provide a method for determining the energy storage repeated fracturing mode, including:

[0007] The sealed target core sample was subjected to repeated energy storage fracturing in different ways, and the target core sample had initial fracture characteristic data;

[0008] Determine the fracture zone of the target core sample after repeated fracturing using different energy storage methods and extract the target fracture characteristic data of the fracture zone;

[0009] Based on the initial fracture characteristic data and the target fracture characteristic data, comprehensive fracture characteristic data is determined. The comprehensive fracture characteristic data is used to determine the fracturing effect of different energy storage repeated fracturing methods.

[0010] By comparing comprehensive fracture characteristic data, the target energy storage repeated fracturing method is selected based on the comparison results.

[0011] In one embodiment, the method further includes:

[0012] Obtain a target core sample, which is a core sample containing initial fractures formed after hydraulic fracturing;

[0013] Steel balls are laid on the initial fractures of the target core sample, and the size of the steel balls is determined based on the initial fracture characteristic data.

[0014] The target core sample after steel balls are laid is sealed to form a sealed target core sample.

[0015] The different methods of energy-storage repeated fracturing include energy-storage repeated fracturing before fracturing, energy-storage repeated fracturing after temporary plugging of the fracture opening and then fracturing, and energy-storage repeated fracturing after temporary plugging of the fracture opening and then energy-storage repeated fracturing. Correspondingly, the different methods of energy-storage repeated fracturing on the sealed target core sample include:

[0016] The sealed target core samples were subjected to repeated energy storage fracturing, including energy storage followed by fracturing, energy storage followed by temporary plugging of the fracture opening and then fracturing, and energy storage followed by temporary plugging of the fracture opening, energy storage followed by fracturing.

[0017] In one embodiment, the energy-storage repeated fracturing method, which involves first temporarily plugging the fracture site and then storing energy before fracturing, includes:

[0018] Fracturing fluid carrying a temporary sealant is injected into the target core sample to temporarily seal the initial fracture opening of the target core sample. The amount of the temporary sealant is determined based on the initial fracture characteristic data of the target core sample.

[0019] An energy storage medium carrying a first tracer is injected into the target core sample to store energy. The first tracer is used to mark the damage and cracks formed during the energy storage process.

[0020] After damage and fractures occur, fracturing fluid carrying a second tracer is injected into the target core sample for repeated fracturing. The second tracer is used to mark the fracturing fractures formed during the repeated fracturing process.

[0021] After the fracturing fracture is formed, the energy storage is stopped and repeated fracturing is carried out.

[0022] In one embodiment, the initial fracture characteristic data of the target core sample includes the initial fracture width and the initial fracture height. Accordingly, the amount of the temporary plugging agent is determined based on the initial fracture characteristic data of the target core sample, including:

[0023] Based on the initial crack height and the initial crack width, the amount of temporary sealant used to seal the crack opening is determined according to the following formula:

[0024] G=(2×h×w×Δd)×ρ s ×(1+k)×(a+b)×10-5

[0025] Where G is the amount of temporary sealant used in the crack; h is the initial crack height; w is the initial crack width; k is the embedding ratio in the crack; Δd is the thickness of the filter cake used for compaction after temporary sealing; ρ s denoted as the apparent density of the temporary sealant at the joint; a and b are fixed constants.

[0026] In one embodiment, the target fracture feature data includes the fracturing fracture deflection angle. Correspondingly, determining the fracture zone of the target core sample after repeated energy storage fracturing using different methods and extracting the target fracture feature data of the fracture zone includes:

[0027] The target core samples after repeated fracturing using different energy storage methods were scanned sequentially to obtain multiple sets of three-dimensional images;

[0028] According to the preset grayscale threshold, the corresponding crack area is extracted from multiple sets of three-dimensional images in sequence;

[0029] Identify the crack surface in the crack zone and convert the corresponding binarized image of the crack surface into a point cloud dataset;

[0030] Select adjacent point cloud data from the point cloud dataset and calculate the crack surface normal vector based on the adjacent point cloud data;

[0031] Obtain the direction of maximum principal stress, and then calculate the deflection angle of the hydraulic fracturing fracture based on the fracture surface normal and the direction of maximum principal stress.

[0032] In one embodiment, the initial crack feature data and the target crack feature data have a one-to-one correspondence. Accordingly, determining the comprehensive crack feature data based on the initial crack feature data and the target crack feature data includes:

[0033] Based on the one-to-one correspondence between the initial crack feature data and the target crack feature data, the target crack feature data and the corresponding initial crack feature data are sequentially subjected to difference processing to obtain multiple sets of difference processing results.

[0034] The results of multiple sets of difference processing are used as comprehensive crack feature data.

[0035] In one embodiment, the method further includes:

[0036] Different energy storage conditions were selected to carry out repeated fracturing with different energy storage methods under different energy storage conditions. The energy storage conditions included energy storage time, injection rate, and energy storage cycles.

[0037] Determine the target fracture characteristic data of fracturing fractures formed by repeated fracturing under different energy storage conditions and with different methods;

[0038] The target fracture feature data of the fracturing fractures formed by repeated fracturing under different energy storage conditions are compared to select the target repeated fracturing mode from the comparison results.

[0039] On the other hand, embodiments of this specification also provide a device for determining the energy storage repetitive fracturing mode, comprising:

[0040] The repeated fracturing module is used to perform energy-storage repeated fracturing on a sealed target core sample in different ways, wherein the target core sample has initial fracture characteristic data;

[0041] The extraction module is used to identify the fracture zone of the target core sample after repeated energy storage fracturing in different ways and extract the target fracture feature data of the fracture zone.

[0042] The determination module is used to determine comprehensive fracture characteristic data based on initial fracture characteristic data and target fracture characteristic data. The comprehensive fracture characteristic data is used to determine the fracturing effect of different energy storage repeated fracturing methods.

[0043] The selection module is used to compare comprehensive fracture characteristic data and select the target energy storage repeated fracturing method based on the comparison results.

[0044] Furthermore, embodiments of this specification also provide an electronic device, including a processor and a memory for storing processor-executable instructions, wherein the processor executes the instructions to implement the method for determining the energy storage repeated fracturing mode in the above embodiments.

[0045] Furthermore, embodiments of this specification also provide a computer-readable storage medium storing computer instructions thereon, wherein the computer-readable storage medium, when executing the instructions, implements the method for determining the energy storage repeated fracturing mode in the above embodiments.

[0046] This specification provides a method and apparatus for determining a cyclic fracturing mode using energy storage. First, a sealed target core sample is subjected to cyclic fracturing using different methods, and the target core sample has initial fracture characteristic data. Second, the fracture zones of the target core sample after cyclic fracturing using different methods are determined, and target fracture characteristic data of the fracture zones are extracted. Then, based on the initial fracture characteristic data and the target fracture characteristic data, comprehensive fracture characteristic data is determined, which is used to determine the fracturing effect of different methods of cyclic fracturing using energy storage. Finally, based on the comprehensive fracture characteristic data, a target cyclic fracturing mode is selected from the different methods of cyclic fracturing using energy storage. In this specification, by performing cyclic fracturing using energy storage on a sealed target core sample, cyclic fracturing can be simulated in the laboratory, and the synergistic effect of energy storage and temporary plugging on fracture propagation and reversal during cyclic fracturing can be evaluated, improving fracturing effect and increasing oil well productivity. By employing different methods of cyclic fracturing using energy storage, the physical process of cyclic fracturing can be observed comprehensively and intuitively. By combining the initial fracture characteristic data and target fracture characteristic data of the target core sample, the fracturing effect of different energy storage repeated fracturing methods can be determined. Therefore, the optimal energy storage repeated fracturing method can be selected based on the fracturing effect of different methods, providing technical support for exploring the mechanism of energy storage repeated fracturing and guiding its field application. Attached Figure Description

[0047] To more clearly illustrate the embodiments of this specification, the accompanying drawings used in the embodiments will be briefly introduced below. The drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a flowchart illustrating a method for determining an energy storage repeated fracturing mode provided in the embodiments of this specification;

[0049] Figure 2 This is a schematic diagram of the energy storage and repeated fracturing method provided in the embodiments of this specification;

[0050] Figure 3 This is a schematic diagram of the energy-storage repeated fracturing method provided in the embodiments of this specification, which involves first storing energy, then temporarily plugging the fracture opening, and then fracturing again.

[0051] Figure 4 This is a schematic diagram of the energy-storage repeated fracturing method provided in the embodiments of this specification, which involves first temporarily plugging the fracture opening, then storing energy, and finally fracturing again.

[0052] Figure 5 This is a schematic diagram of the structural composition of a device for determining an energy storage repeated fracturing mode provided in the embodiments of this specification;

[0053] Figure 6 This is a schematic diagram of the structural composition of the electronic device provided in the embodiments of this specification. Detailed Implementation

[0054] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this specification.

[0055] Low-permeability, ultra-low-permeability, and tight oil and gas reservoirs play a crucial role in oil and gas field development, accounting for a significant portion of their oil and gas reserves. These unconventional oil and gas resources require advanced extraction technologies and suffer from poor reservoir properties. To obtain industrial-grade oil and gas flow, large-scale volumetric fracturing is necessary to improve reservoir fluid permeability. Fracturing tight oil and gas wells face challenges such as depletion-driven development, severe formation depletion, rapid decline in well production, and low recovery rates. Energy storage is needed to replenish reservoir energy and enhance production. In older wells, after initial fracturing, most of the crude oil is extracted along the original fracture direction, leaving residual oil enriched on both sides of the fracture. Repeated fracturing requires redirecting the fractures to utilize the remaining oil-rich areas and increase well productivity. Therefore, repeated fracturing with energy storage can improve reservoir stimulation while simultaneously replenishing formation energy and redirecting fractures, thereby enhancing well production stability.

[0056] Injecting storage fluid into the reservoir before repeated fracturing for well suffocation can effectively replenish formation energy, reduce reservoir fracturing pressure, and minimize rock damage. During well suffocation, the storage fracturing fluid seeps and diffuses, altering the stress field distribution, and can influence fracture propagation and direction after repeated fracturing.

[0057] Currently, due to the lack of physical simulation experiments for energy storage retrieval fracturing, the synergistic effect of energy storage and temporary plugging on the propagation and reorientation of new fractures during energy storage retrieval fracturing in production wells is poorly understood. Most existing laboratory retrieval fracturing experiments employ temporary plugging, which cannot simulate the energy storage process; fluid can break through along the fracture to the core surface, leading to energy storage failure. Furthermore, there is a lack of technical means to evaluate the reorientation of energy storage in retrieval fracturing, making it impossible to assess the synergistic effect of energy storage and temporary plugging on the propagation and reorientation of new fractures, or to select the optimal energy storage retrieval fracturing method to provide guidance for fracturing operations and optimize production enhancement.

[0058] To address the aforementioned problems with existing methods, this specification introduces a method and apparatus for determining the energy storage retrieval fracturing mode. By sealing the core after the initial fracturing, the physical process of energy storage retrieval fracturing in production wells under real reservoir conditions is simulated. This allows for a direct understanding of the synergistic effect of energy storage and temporary plugging on the direction and propagation of new fractures, and enables the selection of the optimal energy storage retrieval fracturing mode. This provides technical support for exploring the mechanism of energy storage retrieval fracturing and the direction and propagation of new fractures after energy storage, and for guiding the field application of energy storage retrieval fracturing.

[0059] Based on the above approach, this specification proposes a method for determining the energy storage repeated fracturing mode. First, a sealed target core sample is subjected to different energy storage repeated fracturing methods. The target core sample has initial fracture characteristic data. Second, the fracture zones of the target core sample after different energy storage repeated fracturing methods are determined, and target fracture characteristic data of the fracture zones are extracted. Then, based on the initial fracture characteristic data and the target fracture characteristic data, comprehensive fracture characteristic data is determined. This comprehensive fracture characteristic data is used to determine the fracturing effect of different energy storage repeated fracturing methods. Finally, based on the comprehensive fracture characteristic data, a target energy storage repeated fracturing mode is selected from the different energy storage repeated fracturing methods. (See reference...) Figure 1 As shown in the embodiments of this specification, a method for determining the energy storage repetitive fracturing mode is provided. In specific implementation, this method may include the following:

[0060] S101: The sealed target core sample is subjected to repeated energy storage fracturing in different ways, and the target core sample has initial fracture characteristic data.

[0061] In some embodiments, the target core sample can be dense sandstone, shale, carbonate rock, etc., and the sample shape can be cylindrical or cubic, which is not specifically limited in this specification. For example, the target core sample can be a 100mm*150mm (mm) cylindrical rock sample or a 300mm*300mm*300mm cubic rock sample. The target core sample can be a core sample containing initial fractures formed after hydraulic fracturing. The target core sample can be subjected to hydraulic fracturing only once or multiple times. To avoid confusion with fractures formed by subsequent repeated hydraulic fracturing, the fractures formed after one or more hydraulic fracturing operations can be uniformly defined as the initial fractures of the target core sample, or uniformly defined as the old fractures of the target core sample. The fractures formed by subsequent repeated hydraulic fracturing are defined as fracturing fractures or new fractures, which is not specifically limited in this specification.

[0062] It should be noted that there may be multiple target core samples with similar properties. Different target core samples can be used for different types of energy storage repeated fracturing to ensure the accuracy of the energy storage repeated fracturing experiment.

[0063] In some embodiments, before performing repeated energy storage fracturing on the sealed target core sample in different ways, the specific implementation may further include:

[0064] Obtain a target core sample, which is a core sample containing initial fractures formed after hydraulic fracturing;

[0065] Steel balls are laid on the initial fractures of the target core sample, and the size of the steel balls is determined based on the initial fracture characteristic data.

[0066] The target core sample after steel balls are laid is sealed to form a sealed target core sample.

[0067] In some embodiments, steel balls can be first laid on the initial fractures of the target core sample before sealing the sample. The size of the steel balls can be determined based on the initial fracture characteristic data; for example, the size can be selected based on the average fracture width, and the diameter of the selected steel balls can be less than or equal to the average fracture width. By laying steel balls, even when the target core sample is subjected to stress, the initial fractures can maintain a certain width, allowing the subsequent temporary sealing agent to smoothly enter the initial fractures and temporarily seal them. It should be noted that for repeated fracturing involving energy storage followed by fracturing, no temporary plugging agent is required during the repeated fracturing process. Therefore, steel balls do not need to be placed in the initial fracture of the target core sample before repeated fracturing involving energy storage followed by fracturing. However, for repeated fracturing involving energy storage followed by temporary plugging of the fracture opening and then fracturing, or for repeated fracturing involving temporary plugging of the fracture opening followed by energy storage and then fracturing, temporary plugging agent is required during the repeated fracturing process. Therefore, steel balls can be placed in the initial fracture of the target core sample before repeated fracturing involving energy storage followed by temporary plugging of the fracture opening and then fracturing.

[0068] In some embodiments, the above-mentioned sealing of the target core sample after steel ball placement to form a sealed target core sample may include: sealing the target core sample after steel ball placement with high-strength epoxy resin to form a sealed target core sample.

[0069] In some embodiments, high-strength epoxy resin can be used to seal the target core sample, fixing the initial fracture tip and the entire initial fracture to form a sealed target core sample. By first sealing the target core sample and then conducting indoor energy storage repeated fracturing experiments on the sealed target core sample, it is possible to ensure uniform stress throughout the core, allowing all the energy storage fluid to be retained inside the core, thus achieving the function of energy storage.

[0070] Of course, provided that the strength of the seal is guaranteed after preparation, other products can also be used to prepare the sealing material in other proportions. This instruction manual does not make specific restrictions on this.

[0071] In some embodiments, sealing the target core sample with high-strength epoxy resin may include: placing the target core sample into a mold that matches its sample shape, slowly pouring the high-strength epoxy resin prepared above into the mold, letting it stand for 120 hours until the peak strength of the epoxy resin is reached, and then demolding the target rock sample to form a sealed target core sample.

[0072] By using high-strength epoxy resin to seal the core (or seal the core), it is possible to prevent the liquid in the confining chamber from communicating with the pressure inside the wellbore before the experiment. At the same time, during the energy storage process, it is possible to prevent the energy storage medium (liquid or gas) from overflowing through the initial cracks of the target core sample after the initial fracturing.

[0073] In some embodiments, the above-mentioned different methods of energy storage and repeated fracturing can include: energy storage and repeated fracturing with energy storage followed by fracturing, energy storage and repeated fracturing with energy storage followed by temporary plugging of the fracture opening and then fracturing, and energy storage and repeated fracturing with temporary plugging of the fracture opening followed by energy storage and then fracturing. Specifically, energy storage and repeated fracturing with energy storage followed by fracturing refers to: first injecting different energy storage media to store energy in the initial fracture (old fracture) and matrix core of the sealed target core sample, and then injecting fracturing fluid to repeatedly fracture the target core sample. Energy storage and repeated fracturing with energy storage followed by temporary plugging of the fracture opening and then fracturing refers to: first injecting different energy storage media to store energy in the initial fracture (old fracture) and matrix core of the sealed target core sample, then pumping in a temporary plugging agent to temporarily seal the fracture opening of the initial fracture (old fracture) of the target core sample, and then injecting fracturing fluid to repeatedly fracture the target core sample. The energy storage and repeated fracturing technique, which involves temporarily plugging the fracture opening before fracturing again, refers to the following: first, a temporary plugging agent is pumped into the fracture opening to temporarily seal the initial fracture (old fracture) of the target core sample; then, different energy storage media are injected to store energy in the sealed initial fracture (old fracture) and matrix core of the target core sample; finally, fracturing fluid is injected to repeatedly fracture the target core sample. The energy storage media can include liquids such as clean water, produced water, flowback fluid, and fracturing fluid, as well as gases such as nitrogen, carbon dioxide, and natural gas; this specification does not specify a particular type. The specific steps for energy storage and repeated fracturing techniques—namely, energy storage followed by temporary plugging and then fracturing, and temporary plugging followed by temporary plugging and then fracturing—will be explained separately later and will not be repeated here.

[0074] It should be noted that the methods of energy storage repeated fracturing are not limited to the examples above. Those skilled in the art may make other changes based on the technical essence of the embodiments in this specification. For example, energy storage and multi-stage temporary plugging (temporary plugging at the fracture opening and temporary plugging inside the fracture) can be combined to form energy storage repeated fracturing with energy storage first, then multi-stage temporary plugging, and then fracturing, or energy storage repeated fracturing with multi-stage temporary plugging first, then energy storage, and then fracturing. However, as long as the functions and effects achieved are the same as or similar to those in the embodiments of this specification, they should be covered within the protection scope of the embodiments of this specification.

[0075] In some embodiments, the initial fracture characteristic data of the target core sample may include at least one of the following: the fractal dimension corresponding to the initial fracture, the initial fracture volume, the volume fraction of the initial fracture, the initial fracture length, the initial fracture width, the initial fracture height, the average fracture width corresponding to the initial fracture, the initial fracture surface deflection angle, etc., which are not specifically limited in this specification. The method of obtaining the initial fracture characteristic data may be the same as the method of obtaining the subsequent target fracture characteristic data, which will be explained separately later, and will not be repeated in this specification.

[0076] In some embodiments, before performing different types of energy storage fracturing on the sealed target core sample, the completion status of the target core sample can be checked to ensure that the target core sample retains an intact wellbore and that the cementing condition is good. Otherwise, it is necessary to reset or reinforce the wellbore and perform cementing operations on the target core sample (cementing can prevent fracturing fluid leakage along the wellbore and improve the stability of the wellbore). The simulated wellbore can be used to simulate the real wellbore of actual energy storage fracturing. The simulated wellbore is hollow inside, and its size can be smaller than the size of the simulated wellbore. One end of the simulated wellbore can be fixed inside the simulated wellbore, and the other end can be used to connect the pipeline of the high-temperature and high-pressure energy storage fracturing equipment. The simulated wellbore and the simulated wellbore can be bonded together with adhesive, and after standing for a period of time, the simulated wellbore and the simulated wellbore can be well sealed, achieving the purpose of cementing.

[0077] In some embodiments, the above-mentioned repeated fracturing with energy storage followed by fracturing, repeated fracturing with energy storage followed by temporary plugging of the fracture opening and then fracturing, and repeated fracturing with temporary plugging of the fracture opening followed by energy storage and then fracturing all require pre-fracturing preparations before carrying out repeated fracturing. For example, the sealed target core sample can be connected to the high-temperature and high-pressure energy storage fracturing equipment; the heating power supply of the high-temperature and high-pressure energy storage fracturing equipment can be turned on to heat it to the experimental set temperature; back pressure and confining pressure can be applied to the energy storage fracturing equipment to the experimental set pressure; the acoustic emission monitoring device and the bottom hole pressure monitoring device can be turned on to monitor the internal pressure of the target core sample, record the changes in injection pressure during energy storage and fracturing, and record the fracturing curve and fracture propagation process, etc.

[0078] In some embodiments, after completing the above-described pre-fracturing preparations, for energy-storage repeated fracturing followed by energy storage, the specific steps of repeated fracturing may include:

[0079] (1) Energy storage: Open the energy storage fluid injection system and inject the energy storage medium into the target core sample through the energy storage pipeline at a constant flow to store energy. After reaching the preset energy storage pressure, stop the pump and record parameters such as the energy storage cycle, energy storage time and energy storage liquid volume.

[0080] (2) Repeated fracturing: Open the fracturing fluid injection system and inject fracturing fluid into the target core sample through the fracturing pipeline at a constant flow rate (discharge rate greater than the energy storage discharge rate) to repeatedly fracture the target core sample;

[0081] (3) Unload the pressure of the energy storage fracturing equipment, stop heating, and take out the target core sample.

[0082] For repeated fracturing involving energy storage followed by temporary plugging of the fracture opening and then fracturing, the specific steps of repeated fracturing may include:

[0083] (1) Energy storage: Open the energy storage fluid injection system and inject the energy storage medium into the target core sample through the energy storage pipeline at a constant flow. After reaching the preset energy storage pressure, stop the pump and record parameters such as energy storage cycle, energy storage time and energy storage liquid volume.

[0084] (2) Temporary plugging of old fracture openings: Open the fracturing fluid injection system and inject fracturing fluid carrying a temporary plugging agent into the target core sample through the fracturing pipeline at a constant flow (discharge rate greater than the energy storage discharge rate) to temporarily plug the fracture openings or initial fracture openings of the target core sample.

[0085] (3) Repeated fracturing: Open the fracturing fluid injection system and inject fracturing fluid into the target core sample through the fracturing pipeline at a constant flow (discharge rate greater than the energy storage discharge rate) to repeatedly fracture the target core sample;

[0086] (4) Unload the pressure of the energy storage fracturing equipment, stop heating, and take out the target core sample.

[0087] For repeated fracturing involving temporary plugging of the fracture opening followed by energy storage and then fracturing, the specific steps of repeated fracturing may include:

[0088] (1) Temporary plugging of old fracture openings: Open the fracturing fluid injection system and inject fracturing fluid carrying a temporary plugging agent into the target core sample through the fracturing pipeline at a constant flow (discharge rate greater than the energy storage discharge rate) to temporarily plug the fracture openings or initial fracture openings of the target core sample.

[0089] (2) Energy storage: Open the energy storage fluid injection system and inject the energy storage medium into the target core sample through the energy storage pipeline at a constant flow. After reaching the preset energy storage pressure, stop the pump and record parameters such as energy storage cycle, energy storage time and energy storage liquid volume.

[0090] (3) Repeated fracturing: Open the fracturing fluid injection system and inject fracturing fluid into the target core sample through the fracturing pipeline at a constant flow (discharge rate greater than the energy storage discharge rate) to repeatedly fracture the target core sample;

[0091] (4) Unload the pressure of the energy storage fracturing equipment, stop heating, and take out the target core sample.

[0092] In some embodiments, during the energy storage retrieval fracturing process, acoustic emission monitoring and bottom hole pressure monitoring devices can be combined to monitor in real time the number, location, and propagation path of new fractures, as well as the propagation time, fracture distribution, and fracturing pressure of each deflecting fracture. By monitoring the number, location, and propagation path of new fractures, as well as the propagation time, fracture distribution, and fracturing pressure of each deflecting fracture, a reference can be provided for subsequently selecting the optimal energy storage retrieval fracturing method.

[0093] In some embodiments, the above-mentioned energy-storage repeated fracturing, which involves temporarily plugging the fracture opening before energy storage and then fracturing, may include, in specific implementation:

[0094] Fracturing fluid carrying a temporary sealant is injected into the target core sample to temporarily seal the initial fracture opening of the target core sample. The amount of the temporary sealant is determined based on the initial fracture characteristic data of the target core sample.

[0095] An energy storage medium carrying a first tracer is injected into the target core sample to store energy. The first tracer is used to mark the damage and cracks formed during the energy storage process.

[0096] After damage and fractures occur, fracturing fluid carrying a second tracer is injected into the target core sample for repeated fracturing. The second tracer is used to mark the fracturing fractures formed during the repeated fracturing process.

[0097] After the fracturing fracture is formed, the energy storage is stopped and repeated fracturing is carried out.

[0098] In some embodiments, for repeated fracturing involving temporary plugging of fracture openings followed by energy storage and then fracturing: Before temporary plugging of the fracture openings, a temporary plugging agent can be added to the fracturing fluid. The temporary plugging agent and the fracturing fluid are mixed. During the temporary plugging process, the fracturing fluid carrying the temporary plugging agent can be injected into the target core sample. The temporary plugging agent can temporarily plug the opening of the initial fracture in the target core sample (or temporarily plug the opening of an old fracture in the target core sample). Before energy storage, a first tracer (or a first dye) can be added to the energy storage medium. The first tracer or the first dye is mixed with the energy storage medium. During the energy storage process, the energy storage medium carrying the first tracer or the first dye can be injected into the target core sample for energy storage. The first tracer or the first dye can be used to mark the damaged fractures during the energy storage process. After energy storage (or after the appearance of fracture loss) or before repeated fracturing, a second tracer (or a second dye) can be added to the fracturing fluid (the fracturing fluid can be a newly acquired fracturing fluid without temporary plugging agent at the fracture site). The second tracer or dye is mixed with the fracturing fluid. During repeated fracturing, the fracturing fluid carrying the second tracer or dye can be injected into the target core sample for repeated fracturing. The second tracer or dye can be used to mark the fracturing fractures formed during the repeated fracturing process. Energy storage and repeated fracturing can be stopped after fracturing fractures appear (or when the target core sample breaks). When the core breaks, a sharp drop in the fracturing pressure curve can be monitored. At this point, the experiment can be stopped, and the target core sample can be removed for subsequent scanning and calculation of the target fracture characteristic data of the target core sample after energy storage and repeated fracturing. The first tracer or first stain and the second tracer or second stain are of different types or colors. Adding the first tracer or first stain and the second tracer or second stain can distinguish between damage fractures formed during energy storage and fracturing fractures formed during repeated fracturing. Repeated fracturing experiments can be conducted using high-temperature, high-pressure energy storage fracturing equipment. Then, CT scans of the target core samples after fracturing allow observation of damage fractures formed during energy storage and fracturing fractures formed during fracturing, based on the first tracer or first stain and the second tracer or second stain.

[0099] In some embodiments, the initial fracture characteristic data of the target core sample may include the initial fracture width and the initial fracture height. Accordingly, the amount of the temporary plugging agent is determined based on the initial fracture characteristic data of the target core sample. In specific implementation, it may include:

[0100] Based on the initial crack height and initial crack width, determine the amount of temporary sealant needed for the crack opening using the following formula:

[0101] G=(2×h×w×Δd)×ρ s ×(1+k)×(a+b)×10 -5

[0102] Where G is the amount of temporary sealant used in the crack; h is the initial crack height; w is the initial crack width; k is the embedding ratio in the crack; Δd is the thickness of the filter cake used for compaction after temporary sealing; ρ s ρ represents the apparent density of the temporary sealant at the seam opening; a and b are fixed constants.

[0103] It should be noted that the weight of the temporary sealant for the cracks can be expressed in kg; the initial crack height in mm; the initial crack width in mm; the embedding ratio in %, which can be taken as 56%; the filter cake thickness in cm, which can be determined based on indoor experimental results and field experience, for example, it can be taken as 2.3 cm (the amount of temporary sealant used can ensure that the thickness of all filter cakes after temporary sealing is more than 2.3 cm, so as to effectively seal the cracks that have been pressed open); the apparent density of the temporary sealant can be expressed in g / cm³. 3 a can be 1.3; b can be 1.5.

[0104] In some embodiments, the particle diameter of the aforementioned temporary sealant can be in the range of 1 / 3 to 2 / 3 of the initial fracture width of the target core sample, that is, 1 / 3 to 2 / 3 of the diameter of the steel ball.

[0105] By sealing the target core sample (a core sample containing initial fractures formed after hydraulic fracturing) with high-strength epoxy resin, fluid can be blocked at the fracture tip during intensive energy storage fracturing, thus achieving energy storage. By setting up intensive energy storage fracturing experiments with different methods, the formation mechanism and process of fracturing fractures under different intensive energy storage fracturing methods can be explored. This allows for a direct understanding of the synergistic effect of energy storage and temporary plugging on the direction and propagation of new fractures during intensive fracturing, providing technical support for studying the mechanism of intensive energy storage fracturing and guiding field applications. Setting up different intensive energy storage fracturing methods also lays the foundation for selecting the optimal intensive energy storage fracturing method in the future.

[0106] S102: Determine the fracture zone of the target core sample after repeated fracturing using different energy storage methods and extract the target fracture feature data of the fracture zone.

[0107] In some embodiments, the target fracture feature data may include at least one of the following: fractal dimension corresponding to the fracture, fracture volume, fracture volume fraction, fracture length, fracture width, fracture height, average fracture width, fracture surface deflection angle, etc., which are not specifically limited in this specification.

[0108] In some embodiments, the target fracture feature data may include the fracturing fracture deflection angle. Accordingly, the above-mentioned determination of the fracture zone of the target core sample after repeated fracturing using different methods and extraction of the target fracture feature data of the fracture zone may, in specific implementation, include:

[0109] The target core samples after repeated fracturing using different energy storage methods were scanned sequentially to obtain multiple sets of three-dimensional images;

[0110] According to the preset grayscale threshold, the corresponding crack area is extracted from multiple sets of three-dimensional images in sequence;

[0111] Identify the crack surface in the crack zone and convert the corresponding binarized image of the crack surface into a point cloud dataset;

[0112] Select adjacent point cloud data from the point cloud dataset and calculate the crack surface normal vector based on the adjacent point cloud data;

[0113] Obtain the direction of maximum principal stress, and then calculate the deflection angle of the hydraulic fracturing fracture based on the fracture surface normal and the direction of maximum principal stress.

[0114] In some embodiments, the above scan can be a CT scan. The principle of a CT scan is that an X-ray source emits X-rays to scan the cross-section of a rock sample on a stage. A detector receives the X-rays after their energy has attenuated by the rock and transmits the data to a computer, finally outputting a scanned image of the sample. The degree of X-ray energy attenuation conforms to Lambert-Beer's last law:

[0115] I = I0e uΔx

[0116] Where I0 is the incident intensity of X-rays (in keV); I is the emitted intensity of X-rays (in keV); Δx is the thickness (in cm); and μ is the attenuation coefficient, which is related to the material density and atomic number.

[0117] In some embodiments, firstly, CT scans can be used to reconstruct a series of three-dimensional images (or three-dimensional rock images) from two-dimensional slices after repeated energy storage fracturing. (In the three-dimensional images obtained from CT scans, the internal structure of the rock exhibits different densities; for example, black areas correspond to lower material density, while white areas correspond to higher material density. Therefore, the rock skeleton, pores, and fractures can be distinguished from the three-dimensional image, thus characterizing fracture features under different conditions.) Then, fracture zones (or fracture areas) are extracted from the three-dimensional images using a preset grayscale threshold. Secondly, the fractures can be digitized by setting the unit length of voxels (or basic elements), where the size of a voxel represents the smallest element constituting the image. Finally, a preset algorithm (such as homotopy thinning algorithm) can be used to extract the fracture surface in the fracture zone from the 3D binary image, calculate the center point of each basic element (voxel) on the fracture surface, and then convert the corresponding binary image of the fracture surface into a point cloud dataset. Point cloud data with adjacent positions are selected from the point cloud dataset, and the fracture surface normal vector is calculated based on the adjacent point cloud data. After calculating the fracture surface normal vector, the direction of the maximum horizontal principal stress (which can be a vector pre-selected in 3D space and used as a known quantity) can be combined with the following formula to determine the fracturing fracture deflection angle (the fracture deflection angle can also be used as an indicator of fracture direction):

[0118]

[0119] Where θ is the deflection angle of the fracturing fracture surface; Crack surface normal vector; This is the direction vector of the maximum principal stress.

[0120] It should be noted that the initial crack surface deflection angle can also be calculated using the above formula. Correspondingly, θ in the above formula can also be the initial crack surface deflection angle.

[0121] In some embodiments, after determining the fracture zone of the target core sample after repeated fracturing using different methods, the fractal dimension corresponding to the fracturing fracture can also be determined using the following formula:

[0122]

[0123] Where FD is the fractal dimension corresponding to the fracturing fracture; h is the size of the basic element, which is a box or cube; N h The number of basic elements required to cover the hydraulic fracturing fracture.

[0124] It should be noted that the fractal dimension corresponding to the initial crack can also be calculated using the above formula. Correspondingly, FD in the above formula can also be the fractal dimension corresponding to the initial crack, N.h It can also specify the number of basic elements required to cover the initial crack.

[0125] The fractal dimensions mentioned above (the fractal dimension corresponding to the initial fracture and the fractal dimension corresponding to the hydraulic fracture) are calculated using the box counting method, that is, by changing the size of the basic element h, the number N of different basic elements required to cover the fracture is calculated. h N can be plotted in a double logarithmic graph. h By relating the fractal dimension to h, the slope of the straight line can be derived, thus obtaining the fractal dimension (FD). A larger fractal dimension indicates a more complex crack.

[0126] In some embodiments, after determining the fracture zone of the target core sample following different methods of energy-storage repeated fracturing, the fracturing fracture volume can also be determined using the following formula:

[0127] V f =V0*N t

[0128] Among them, V f V represents the volume of the fracturing fracture; V0 represents the actual volume of each basic element; N represents the volume of the fracture. t The number of basic elements covering the hydraulic fracturing fracture.

[0129] Wherein, V0 can be represented as:

[0130] V0 = s 3

[0131] Where s is the side length of the basic element, the cube.

[0132] It should be noted that the initial crack volume can also be calculated using the above formula. Accordingly, the meaning of the parameters in the above formula needs to be matched with the initial crack and adjusted accordingly, which will not be elaborated here.

[0133] In some embodiments, the volume fraction of the fracturing fractures and the volume fraction of the initial fractures can also be determined using the following formulas:

[0134] α=V f / V s

[0135] Where α is the volume fraction of the hydraulic fracture (or the volume fraction of the initial fracture); V f V represents the volume of the fracturing fracture (or the initial fracture volume); s The effective volume of the target rock sample (the effective volume of the target rock sample is calculated by subtracting the borehole volume from the total volume of the target rock sample).

[0136] In some embodiments, the fracturing fracture width (or initial fracture width) can also be determined using the following formula:

[0137] W = s * N i

[0138] Where W is the width of the hydraulic fracture (or the initial fracture width); s is the side length of the basic element cube; N i This represents the number of basic elements at the same corresponding crack width.

[0139] It should be noted that after obtaining the fracture width (or initial fracture width) at different locations, the maximum, minimum, and average values ​​of the fracture width (or initial fracture width) can be obtained accordingly. These values ​​can be used to characterize the properties of the fracture.

[0140] In some embodiments, the fracturing fracture height (or initial fracture height) can also be determined using the following formula:

[0141] h = s * N j

[0142] Where h is the fracture height (or initial fracture height); s is the side length of the basic element cube; N j This represents the number of basic elements at the same corresponding crack height.

[0143] It should be noted that after obtaining the fracture height (or initial fracture height) at different locations, the maximum, minimum, and average values ​​of the fracture height (or initial fracture height) can be obtained accordingly. These values ​​can be used to characterize the properties of the fracture.

[0144] By obtaining the fractal dimension, volume, volume fraction, width, height, average fracture width, and surface deflection of the fractures in target core samples after repeated energy storage fracturing under different conditions, a foundation can be laid for subsequent analysis of the target fracture characteristics and the initial fracture characteristics, in order to determine the optimal energy storage repeated fracturing method.

[0145] S103: Based on the initial fracture characteristic data and the target fracture characteristic data, determine the comprehensive fracture characteristic data, which is used to determine the fracturing effect of different energy storage repeated fracturing methods.

[0146] In some embodiments, the initial crack feature data and the target crack feature data have a one-to-one correspondence. Accordingly, the determination of comprehensive crack feature data based on the initial crack feature data and the target crack feature data may, in specific implementations, include:

[0147] Based on the one-to-one correspondence between the initial crack feature data and the target crack feature data, the target crack feature data and the corresponding initial crack feature data are sequentially subjected to difference processing to obtain multiple sets of difference processing results.

[0148] The results of multiple sets of difference processing are used as comprehensive crack feature data.

[0149] In some embodiments, the aforementioned one-to-one correspondence means that the initial fracture volume in the initial fracture feature data can correspond to the fracturing fracture volume in the target fracture feature data, and the initial fracture width in the initial fracture feature data can correspond to the fracturing fracture width in the target fracture feature data, etc. The aforementioned method of performing difference processing on the target fracture feature data and the corresponding initial fracture feature data according to the one-to-one correspondence between the initial and target fracture feature data can be understood as: performing difference processing on the fracturing fracture volume and the initial fracture volume (i.e., calculating the difference between the two), or performing difference processing on the fracturing fracture width and the initial fracture width, etc. By performing difference processing on the target fracture feature data and the corresponding initial fracture feature data, multiple sets of difference processing results can be obtained, and these multiple sets of difference processing results can be used as comprehensive fracture feature data. Comprehensive fracture feature data can then be used to determine the fracturing effect formed by different methods of energy storage repeated fracturing. For example, a larger difference between the fracturing fracture volume and the initial fracture volume, or a larger difference between the fracturing fracture width and the initial fracture width, indicates a better energy storage repeated fracturing effect. It should be noted that the size of the target fracture feature data extracted from the fracture zone of different energy storage retrieval fracturing methods is different. The target fracture feature data extracted from the energy storage retrieval fracturing method of first energy storage and then fracturing can be subtracted from the corresponding initial fracture feature data to obtain the difference data set A (or the first difference data set). The target fracture feature data extracted from the energy storage retrieval fracturing method of first energy storage and then temporary plugging of the fracture opening and then fracturing can be subtracted from the corresponding initial fracture feature data to obtain the difference data set B (or the second difference data set). The target fracture feature data extracted from the energy storage retrieval fracturing method of first temporary plugging of the fracture opening and then energy storage and then fracturing can be subtracted from the corresponding initial fracture feature data to obtain the difference data set C (or the third difference data set). The difference data sets A, B, and C (or the first difference data set, the second difference data set, and the third difference data set) can be used as the comprehensive fracture feature data.

[0150] By acquiring comprehensive fracture characteristic data, we can lay the foundation for a simple, fast, and intuitive selection of the optimal energy storage cyclic fracturing method.

[0151] In some embodiments, the initial fracture and the hydraulic fracturing fracture of the target core sample can be non-overlapping. If the initial fracture and the hydraulic fracturing fracture are non-overlapping, it indicates successful energy storage repeated fracturing. Under the condition that all energy storage repeated fracturing methods are successful, the aforementioned initial fracture characteristic data and the aforementioned target fracture characteristic data can be compared to accurately and effectively select the optimal energy storage repeated fracturing method.

[0152] In some embodiments, the overlap of the initial fracture and the fracturing fracture indicates a failure of energy storage repeated fracturing. Given the existence of energy storage repeated fracturing failures in different methods, the optimal energy storage repeated fracturing method can be selected when the initial fracture and the fracturing fracture do not overlap. By selecting the optimal energy storage repeated fracturing method based on the overlap of the initial fracture and the fracturing fracture under the condition of energy storage repeated fracturing failures, the selection efficiency and accuracy of the optimal energy storage repeated fracturing method can be improved.

[0153] S104: Compare the comprehensive fracture characteristic data and select the target energy storage repeated fracturing method based on the comparison results.

[0154] In some embodiments, the aforementioned comprehensive fracture characteristic data may be a first set of difference data related to repeated fracturing with energy storage followed by fracturing, a second set of difference data related to repeated fracturing with energy storage followed by temporary plugging of the fracture opening and then fracturing, and a third set of difference data related to repeated fracturing with energy storage followed by temporary plugging of the fracture opening and then energy storage and then fracturing. The comparison of the comprehensive fracture characteristic data may involve comparing the data in the first set of difference data related to repeated fracturing with energy storage followed by fracturing with a corresponding first preset difference threshold. For example, comparing the difference between the fracture volume and the initial fracture volume with a preset volume difference threshold, or comparing the difference between the fracture width and the initial fracture width with a preset width difference threshold. If the comparison result is greater than the corresponding first preset difference threshold, it indicates that the repeated fracturing with energy storage followed by fracturing has a good effect. The system can also compare data from the second difference dataset related to repeated fracturing involving energy storage followed by temporary sealing of the fracture opening and then fracturing with the corresponding second preset difference threshold. Similarly, it can compare data from the third difference dataset related to the same process with the corresponding third preset difference threshold. It should be noted that the first, second, and third preset difference thresholds can all include volume difference thresholds, width difference thresholds, and height difference thresholds. These thresholds can be set according to actual needs, and this specification does not impose specific limitations. However, the values ​​of the volume difference threshold, width difference threshold, and height difference threshold set in the first, second, and third preset difference thresholds can be different. The data types in the first, second, and third difference datasets can be the same, but the sizes of data of the same type can differ.

[0155] After comparing the data in the first difference dataset related to intensive energy storage fracturing followed by fracturing with the corresponding first preset difference threshold, comparing the data in the second difference dataset related to intensive energy storage fracturing followed by fracture plugging with the corresponding second preset difference threshold, and comparing the data in the third difference dataset related to intensive energy storage fracturing followed by fracture plugging with the corresponding third preset difference threshold, we can further compare which type of intensive energy storage fracturing has the most data exceeding the corresponding preset threshold in its comprehensive fracture characteristic data. Therefore, we can select the target intensive energy storage fracturing method from the comparison results. The optimal energy storage repeated fracturing method is the one that involves energy storage followed by fracturing. For example, in the case of energy storage repeated fracturing where energy storage precedes fracturing, only the volume difference of the fracture exceeds the preset volume difference threshold. In other words, in the case of energy storage repeated fracturing where energy storage precedes fracturing, only the fracture volume changes significantly. However, in the case of energy storage repeated fracturing where energy storage precedes temporary plugging of the fracture opening followed by fracturing, not only does the fracture volume change significantly, but the fracture width and height also change significantly. Furthermore, in the case of energy storage repeated fracturing where the fracture opening is temporarily plugged before energy storage precedes fracturing, not only does the fracture volume change significantly, but the fracture width and height also change significantly, as do the fractal dimension and fracture deflection angle. Therefore, it can be determined that the energy storage repeated fracturing method of temporarily plugging the fracture opening before energy storage precedes fracturing is the optimal energy storage repeated fracturing method.

[0156] It should be noted that the determination of the optimal energy storage repeated fracturing method is not limited to the examples above. Those skilled in the art may make other changes based on the technical essence of the embodiments in this specification (e.g., when the data in the comprehensive fracture characteristic data of different energy storage repeated fracturing methods are all greater than the corresponding preset threshold, the numerical values ​​of the comprehensive fracture characteristic data can be compared, and the energy storage repeated fracturing method corresponding to the largest value can be taken as the optimal energy storage repeated fracturing method). However, as long as the function and effect achieved are the same as or similar to the embodiments in this specification, they should be covered within the protection scope of the embodiments in this specification.

[0157] By comprehensively analyzing the target fracture characteristic data and initial fracture characteristic data extracted from different energy storage cyclic fracturing methods, and determining the comprehensive fracture characteristic data, we can analyze the synergistic effect of energy storage and temporary plugging on fracture propagation based on the comprehensive fracture characteristic data. We can also intuitively understand the fracture initiation, diversion and propagation laws of fractures in the process of energy storage diversion cyclic fracturing under the synergistic effect of energy storage and temporary plugging. This provides an experimental method for exploring the mechanism of energy storage diversion cyclic fracturing and guiding the field application of energy storage diversion cyclic fracturing.

[0158] In some embodiments, the above-mentioned selection of the target energy storage re-fracturing method may further include, in specific implementation:

[0159] Different energy storage conditions were selected to carry out repeated fracturing with different energy storage methods under different energy storage conditions. The energy storage conditions included energy storage time, injection rate, and energy storage cycles.

[0160] Determine the target fracture characteristic data of fracturing fractures formed by repeated fracturing under different energy storage conditions and with different methods;

[0161] The target fracture feature data of the fracturing fractures formed by repeated fracturing under different energy storage conditions are compared to select the target repeated fracturing mode from the comparison results.

[0162] In some embodiments, the above-mentioned energy storage conditions may also include parameters such as the amount of energy storage liquid, which are not specifically limited in this specification.

[0163] In some embodiments, different energy storage conditions can be selected, such as different energy storage times, injection rates, energy storage cycles, and energy storage fluid volumes. Then, energy storage repeated fracturing can be carried out under different energy storage conditions and different coupling methods. Then, the target fracture characteristic data of the fracturing fractures formed by energy storage repeated fracturing under different energy storage conditions and different coupling methods can be compared. Finally, based on the comparison results, it can be explored which energy storage repeated fracturing method and under which energy storage conditions has the best effect. Finally, the optimal energy storage repeated fracturing method and the optimal energy storage conditions can be selected simultaneously, and the optimal energy storage repeated fracturing method and the optimal energy storage conditions can be taken as the best combination.

[0164] The above method will be described below with reference to a specific embodiment. However, it is worth noting that this specific embodiment is only for better illustration of this application and does not constitute an improper limitation of this application.

[0165] Before implementation, a hydraulically fracturing core sample containing fractures can be obtained. This sample is then subjected to CT scanning, and the resulting 3D grayscale image is processed. Image processing software is then used to characterize and reconstruct the initial fractures in the core sample, calculating initial fracture volume, width, height, direction (angle between the fracture surface normal and the direction of maximum principal stress), number of fractures, and fractal dimension. Before repeated fracturing, the well completion status of the core sample can be checked to ensure that the wellbore remains intact and cemented wells are in good condition. Before repeated fracturing, steel balls can be evenly placed within the initial fractures of the core sample and fixed to the fracture surface to support the initial fractures, ensuring a certain fracture width under stress loading. Finally, high-strength epoxy resin can be used to encapsulate the core sample after hydraulic fracturing.

[0166] In practical implementation, firstly, different methods of energy-storage repeated fracturing experiments can be conducted on the sealed target core sample. For example, a high-temperature, high-pressure energy-storage fracturing device can be used to conduct an energy-storage repeated fracturing experiment on the sealed target core sample, where energy is first stored and then temporarily plugged at the fracture site before fracturing. Alternatively, an energy-storage repeated fracturing experiment can be conducted on the sealed target core sample, where energy is first stored, then the fracture site is temporarily plugged, and then energy is stored before fracturing. Then, CT scans and reconstructions can be performed on the target core samples after repeated fracturing with energy storage to obtain the three-dimensional fracture propagation morphology and calculate its fracture characteristic parameters. Specifically, CT scans can be performed on the target core samples after repeated fracturing to obtain three-dimensional grayscale images, which are then processed. Image processing software is used to characterize and reconstruct the fractures in the target core samples after repeated fracturing, calculating fracture volume, fracture width, fracture height, fracture direction (the angle between the fracture surface normal and the direction of maximum principal stress), number of fractures, and the fractal dimension of the fractures, among other target fracture characteristic data. Finally, the initial and target fracture characteristic data of the target core samples after hydraulic fracturing and repeated fracturing with energy storage can be compared (or contrasted) to determine the comprehensive fracture characteristic data. Based on the comprehensive fracture characteristic data, the synergistic effect of energy storage and temporary plugging on fracture propagation can be analyzed.

[0167] The above methods can be used to conduct multi-mode energy storage repeated fracturing experiments under laboratory conditions. This can be used to simulate the physical process of energy storage repeated fracturing in production wells under real reservoir conditions, intuitively understand the fracture propagation law during the energy storage-to-fracturing process, explore the energy storage-to-fracturing characteristics, and provide support for the optimization of energy storage repeated fracturing technology.

[0168] For a specific scenario example, please refer to Figure 2 As shown, Figure 2 A schematic diagram of energy storage repeated fracturing is shown. Figure 2 In the diagram: 201 is the target core sample; 202 is the simulated wellbore; 203 is the simulated open hole section of the wellbore; 204 is high-strength epoxy resin with an AB glue mass ratio of 2:1; 205 is the initial fracture; 206 is the steel ball; 207 is the energy storage zone; and 208 is the repeated fracturing fracture. Figure 2From left to right, the following steps can be performed: (1) Select steel balls 206 with a diameter less than or equal to the average fracture width and evenly lay them in the initial fracture 205 after hydraulic fracturing to form a core with steel balls laid after hydraulic fracturing. (2) Use high-strength epoxy resin 204 with a mass ratio of AB glue of 2:1 to seal the outside of the target core sample 201 to form a sealed core. (3) After sealing the core with high-strength epoxy resin 204 with a mass ratio of AB glue of 2:1, it can be used in conjunction with a high-temperature and high-pressure energy storage fracturing device to isolate the fluid in the cavity of the energy storage fracturing device, prevent the fluid in the cavity from communicating with the pressure in the simulated wellbore 202 before the experiment, and at the same time ensure that the energy storage medium will not flow out from the initial fracture 205 when the energy storage medium is injected, thereby achieving the purpose of energy storage inside the target core sample 201 and finally forming an energy-storage core. (4) The strength of the high-strength epoxy resin 204 with an AB glue mass ratio of 2:1 is greater than the fracturing pressure of the target core sample 201 of repeated fracturing. When the fracturing fluid is pumped into the simulated wellbore 202 through the fracturing pipeline, the fracturing fluid enters the initial fracture 205 and will be pressurized under the action of the high-strength epoxy resin 204 with an external AB glue mass ratio of 2:1, thereby sealing the fracture end (tip) of the initial fracture 205 (old fracture). After the fracturing fluid is injected, the repeated fracturing fracture 208 (new fracture) can be formed in the presence of the initial fracture 205 (old fracture), thereby achieving the purpose of generating new fractures or changing direction of the repeated fracturing fracture, and finally forming a repeatedly fracturing core.

[0169] Among them, before laying steel balls (1), if the cementing quality of the wellbore after the initial fracturing does not meet the requirements, the target core sample 201 can be subjected to enhanced cementing operation. After cementing and fracturing, it can form Figure 2 Cores obtained from repeated compression fracturing.

[0170] See Figure 3 As shown, Figure 3 A schematic diagram of repeated energy storage fracturing is shown, which involves first storing energy, then temporarily plugging the fracture opening, and then fracturing again. Figure 3 The meanings of 201, 202, 203, 204, 205, 206, 207, and 208 in the text are... Figure 2 The same applies, so this instruction manual will not repeat it here. Figure 3 209 in the formula is a temporary sealant for the seam. Figure 3 From left to right, the following steps can be performed: (1) forming a core after hydraulic fracturing and laying steel balls; (2) forming a sealed core; (3) forming a core after energy storage; (4) forming a core after temporary plugging of the fracture opening; and (5) forming a core after repeated fracturing.

[0171] See Figure 4 As shown, Figure 4 A schematic diagram of energy-storage repeated fracturing is shown, which involves first temporarily plugging the fracture opening, then storing energy, and finally fracturing again. Figure 4The meanings of 201, 202, 203, 204, 205, 206, 207, 208, and 209 in the text are... Figure 3 The same applies, so this instruction manual will not repeat it here. Figure 4 From left to right, the following steps can be performed: (1) forming a core after hydraulic fracturing and laying steel balls; (2) forming a sealed core; (3) forming a core after the fracture opening is temporarily plugged; (4) forming a core after energy storage; and (5) forming a core after repeated fracturing.

[0172] Although this specification provides the following examples or appendices Figure 5 The methods, steps, or apparatus structures shown may include more or fewer combined operational steps or module units based on conventional or non-inventive methods. In steps or structures where there is no logically necessary causal relationship, the execution order of these steps or the module structure of the apparatus is not limited to the execution order or module structure shown in the embodiments or drawings of this specification. When the methods or module structures described are applied in actual devices, servers, or terminal products, they can be executed sequentially or in parallel according to the methods or module structures shown in the embodiments or drawings (e.g., in parallel processor or multi-threaded processing environments, or even distributed processing or server cluster implementation environments).

[0173] Based on the above-described method for determining the energy storage repeated fracturing mode, this specification also provides an embodiment of a device for determining the energy storage repeated fracturing mode. For example... Figure 5 As shown, the device for determining the energy storage re-fracturing mode may specifically include the following modules:

[0174] The repeated fracturing module 501 can be used to perform energy-storing repeated fracturing on a sealed target core sample in different ways, wherein the target core sample has initial fracture characteristic data;

[0175] The extraction module 502 can be used to determine the fracture zone of the target core sample after repeated energy storage fracturing in different ways and extract the target fracture feature data of the fracture zone.

[0176] The determination module 503 can be used to determine comprehensive fracture characteristic data based on initial fracture characteristic data and target fracture characteristic data. The comprehensive fracture characteristic data is used to determine the fracturing effect of different energy storage repeated fracturing methods.

[0177] Module 504 can be selected to compare comprehensive fracture characteristic data and select the target energy storage repeated fracturing method based on the comparison results.

[0178] In some embodiments, the aforementioned repeated fracturing module 501 can also be used to obtain a target core sample, which is a core sample containing initial fractures formed after hydraulic fracturing; steel balls are laid on the initial fractures of the target core sample, the size of which is determined according to the initial fracture characteristic data; the target core sample after laying the steel balls is sealed to form a sealed target core sample; the different energy storage repeated fracturing methods in the aforementioned repeated fracturing module 501 can include energy storage repeated fracturing before fracturing, energy storage repeated fracturing before energy storage and then fracturing, and energy storage repeated fracturing before energy storage and then fracturing. Accordingly, the aforementioned repeated fracturing module 501 can specifically be used to perform energy storage repeated fracturing before energy storage, energy storage repeated fracturing before energy storage and then fracturing, and energy storage repeated fracturing before energy storage and then fracturing on the sealed target core sample.

[0179] In some embodiments, the aforementioned repeated fracturing module 501 may further be used to inject fracturing fluid carrying a temporary plugging agent into the target core sample, using the temporary plugging agent to temporarily plug the initial fracture opening of the target core sample. The amount of the temporary plugging agent is determined based on the initial fracture characteristic data of the target core sample. Energy storage medium carrying a first tracer is injected into the target core sample for energy storage. The first tracer is used to mark damaged fractures formed during the energy storage process. After damaged fractures appear, fracturing fluid carrying a second tracer is injected into the target core sample for repeated fracturing. The second tracer is used to mark fracturing fractures formed during the repeated fracturing process. After fracturing fractures appear, the energy storage and repeated fracturing are stopped.

[0180] In some embodiments, the initial fracture characteristic data of the target core sample may include the initial fracture width and the initial fracture height. Accordingly, the repeated fracturing module 501 may also be used to determine the amount of temporary plugging agent at the fracture opening based on the initial fracture height and the initial fracture width according to the following formula:

[0181] G=(2×h×w×Δd)×ρ s ×(1+k)×(a+b)×10 -5

[0182] Where G is the amount of temporary sealant used in the crack; h is the initial crack height; w is the initial crack width; k is the embedding ratio in the crack; Δd is the thickness of the filter cake used for compaction after temporary sealing; ρ s denoted as the apparent density of the temporary sealant at the joint; a and b are fixed constants.

[0183] In some embodiments, the target fracture feature data may include the fracturing fracture deflection angle. Accordingly, the extraction module 502 may also be used to sequentially scan the target core sample after repeated fracturing using different methods to obtain multiple sets of three-dimensional images; extract the corresponding fracture zone from the multiple sets of three-dimensional images according to a preset grayscale threshold; determine the fracture surface in the fracture zone and convert the binarized image corresponding to the fracture surface into a point cloud dataset; select adjacent point cloud data from the point cloud dataset and calculate the fracture surface normal vector based on the adjacent point cloud data; obtain the direction of maximum principal stress and obtain the fracturing fracture deflection angle based on the fracture surface normal vector and the direction of maximum principal stress.

[0184] In some embodiments, the initial crack feature data and the target crack feature data have a one-to-one correspondence. Accordingly, the determining module 503 can also be used to perform difference processing on the target crack feature data and the corresponding initial crack feature data in sequence according to the one-to-one correspondence between the initial crack feature data and the target crack feature data, to obtain multiple sets of difference processing results; and use the multiple sets of difference processing results as comprehensive crack feature data.

[0185] In some embodiments, the selection module 504 can also be used to select different energy storage conditions and carry out repeated fracturing under different energy storage conditions and in different ways. The energy storage conditions include energy storage time, injection rate, and energy storage cycles. The module can also determine the target fracture feature data of the fracturing fractures formed by repeated fracturing under different energy storage conditions and in different ways. The module can compare the target fracture feature data of the fracturing fractures formed by repeated fracturing under different energy storage conditions and in different ways to select the target repeated fracturing method from the comparison results.

[0186] It should be noted that the units, devices, or modules described in the above embodiments can be implemented by computer chips or physical entities, or by products with certain functions. For ease of description, the above devices are described by dividing them into various modules according to their functions. Of course, in implementing this specification, the functions of each module can be implemented in one or more software and / or hardware, or the module that implements the same function can be implemented by a combination of multiple sub-modules or sub-units, etc. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection between the devices or units shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0187] As can be seen from the above, the device for determining the energy storage retrieval fracturing mode provided in the embodiments of this specification can, on the one hand, simulate the physical process of energy storage redirection retrieval fracturing in production wells under real reservoir conditions, intuitively understand the fracture propagation law during energy storage redirection retrieval fracturing, explore energy storage redirection characteristics, and provide support for optimizing energy storage redirection retrieval fracturing technology. On the other hand, it can provide an experimental means to explore the mechanism of energy storage redirection retrieval fracturing and guide its field application, thereby optimizing the production enhancement effect.

[0188] This specification also provides an electronic device for determining a method of energy storage repeated fracturing, including a processor and a memory for storing processor-executable instructions. Specifically, the processor can execute the following steps according to the instructions: performing energy storage repeated fracturing on a sealed target core sample using different methods, the target core sample having initial fracture characteristic data; determining the fracture zones of the target core sample after different methods of energy storage repeated fracturing and extracting target fracture characteristic data from the fracture zones; determining comprehensive fracture characteristic data based on the initial fracture characteristic data and the target fracture characteristic data, the comprehensive fracture characteristic data being used to determine the fracturing effect of different methods of energy storage repeated fracturing; comparing the comprehensive fracture characteristic data and selecting the target energy storage repeated fracturing method based on the comparison results.

[0189] To execute the above instructions more accurately, please refer to... Figure 6 As shown in the embodiments of this specification, another specific electronic device is also provided, wherein the electronic device includes a network communication port 601, a processor 602, and a memory 603. The above structures are connected by internal cables so that the various structures can perform specific data interaction.

[0190] Specifically, the network communication port 601 can be used to perform repeated energy storage fracturing on the sealed target core sample in different ways, and the target core sample has initial fracture characteristic data.

[0191] The processor 602 can be specifically used to determine the fracture zone of the target core sample after different energy storage repeated fracturing methods and extract the target fracture feature data of the fracture zone; determine comprehensive fracture feature data based on the initial fracture feature data and the target fracture feature data, the comprehensive fracture feature data being used to determine the fracturing effect of different energy storage repeated fracturing methods; compare the comprehensive fracture feature data and select the target energy storage repeated fracturing method based on the comparison results.

[0192] The memory 603 can be used to store the corresponding instruction program.

[0193] In this embodiment, the network communication port 601 can be a virtual port bound to different communication protocols, thereby enabling the sending or receiving of different data. For example, the network communication port can be a port responsible for web data communication, a port responsible for FTP data communication, or a port responsible for email data communication. Furthermore, the network communication port can also be a physical communication interface or communication chip. For example, it can be a wireless mobile network communication chip, such as GSM or CDMA; it can also be a Wi-Fi chip; or it can be a Bluetooth chip.

[0194] In this embodiment, the processor 602 can be implemented in any suitable manner. For example, the processor can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (e.g., software or firmware) executable by the (micro)processor, logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers, etc. This specification is not limiting.

[0195] In this embodiment, the memory 603 may include multiple layers. In a digital system, anything that can store binary data can be a memory. In an integrated circuit, a circuit with storage function but no physical form is also called a memory, such as RAM, FIFO, etc. In a system, a storage device with a physical form is also called a memory, such as a memory stick, TF card, etc.

[0196] This specification also provides a computer storage medium based on the above-described method for determining energy storage repeated fracturing modes. The computer storage medium stores computer program instructions that, when executed, perform the following: energy storage repeated fracturing on a sealed target core sample using different methods, the target core sample having initial fracture characteristic data; determine the fracture zones of the target core sample after different methods of energy storage repeated fracturing and extract target fracture characteristic data from the fracture zones; determine comprehensive fracture characteristic data based on the initial fracture characteristic data and the target fracture characteristic data, the comprehensive fracture characteristic data being used to determine the fracturing effect of different methods of energy storage repeated fracturing; compare the comprehensive fracture characteristic data, and select the target energy storage repeated fracturing mode based on the comparison results.

[0197] In this embodiment, the storage medium includes, but is not limited to, Random Access Memory (RAM), Read-Only Memory (ROM), cache, hard disk drive (HDD), or memory card. The memory can be used to store computer program instructions. The network communication unit can be an interface configured according to standards specified in the communication protocol for network connection communication.

[0198] While this specification provides the steps of operation for the methods described in the embodiments or flowcharts, more or fewer steps may be included based on conventional or non-inventive means. The order of steps listed in the embodiments is merely one possible order of execution among many steps and does not represent the only possible order. In actual device or client product execution, the methods shown in the embodiments or drawings may be executed sequentially or in parallel (e.g., in a parallel processor or multi-threaded processing environment, or even a distributed data processing environment). The terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, product, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, product, or apparatus. Without further limitations, the presence of other identical or equivalent elements in a process, method, product, or apparatus that includes said elements is not excluded. The terms "first," "second," etc., are used to denote names and do not indicate any particular order.

[0199] Those skilled in the art will also know that, besides implementing the controller using purely computer-readable program code, the same functions can be achieved by logically programming the method steps, making the controller function as logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers (PLCs), and embedded microcontrollers. Therefore, such a controller can be considered a hardware component, and the devices within it used to implement various functions can also be considered structures within that hardware component. Alternatively, the devices used to implement various functions can be considered as both software modules implementing the method and structures within a hardware component.

[0200] This specification can be described in the general context of computer-executable instructions that are executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, classes, etc., that perform a specific task or implement a specific abstract data type. This specification can also be practiced in distributed computing environments, where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0201] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that this specification can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solutions of this specification can essentially be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, mobile terminal, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments of this specification.

[0202] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. This specification can be used in numerous general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable electronic devices, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices, etc.

[0203] Although this specification has been described by way of examples, those skilled in the art will recognize that many variations of this specification are possible without departing from its spirit, and it is intended that the appended claims cover such variations without departing from the spirit of this specification.

Claims

1. A method for determining a repetitive energy storage fracturing mode, characterized in that, include: The sealed target core sample was subjected to repeated energy storage fracturing in different ways, and the target core sample had initial fracture characteristic data; Determine the fracture zone of the target core sample after repeated fracturing using different energy storage methods and extract the target fracture characteristic data of the fracture zone; Based on the initial fracture characteristic data and the target fracture characteristic data, comprehensive fracture characteristic data is determined. The comprehensive fracture characteristic data is used to determine the fracturing effect of different energy storage repeated fracturing methods. Compare the comprehensive fracture characteristic data and select the target energy storage repeated fracturing method based on the comparison results; The method further includes: Obtain a target core sample, which is a core sample containing initial fractures formed after hydraulic fracturing; Steel balls are laid on the initial fractures of the target core sample, and the size of the steel balls is determined based on the initial fracture characteristic data. The target core sample after steel balls are laid is sealed to form a sealed target core sample. The different methods of energy-storage repeated fracturing include energy-storage repeated fracturing before fracturing, energy-storage repeated fracturing after temporary plugging of the fracture opening and then fracturing, and energy-storage repeated fracturing after temporary plugging of the fracture opening and then energy-storage repeated fracturing. Correspondingly, the different methods of energy-storage repeated fracturing on the sealed target core sample include: The sealed target core sample was subjected to repeated fracturing with energy storage followed by fracturing, repeated fracturing with energy storage followed by temporary plugging of the fracture opening and then fracturing, and repeated fracturing with energy storage followed by temporary plugging of the fracture opening and then energy storage and then fracturing. The target fracture feature data includes the fracturing fracture deflection angle. Correspondingly, determining the fracture zone of the target core sample after repeated energy storage fracturing using different methods and extracting the target fracture feature data of the fracture zone includes: The target core samples after repeated fracturing using different energy storage methods were scanned sequentially to obtain multiple sets of three-dimensional images; According to the preset grayscale threshold, the corresponding crack area is extracted from multiple sets of three-dimensional images in sequence; Identify the crack surface in the crack zone and convert the corresponding binarized image of the crack surface into a point cloud dataset; Select adjacent point cloud data from the point cloud dataset and calculate the crack surface normal vector based on the adjacent point cloud data; Obtain the direction of maximum principal stress, and then calculate the fracturing fracture deflection angle based on the fracture surface normal vector and the direction of maximum principal stress. The initial crack feature data and the target crack feature data have a one-to-one correspondence. Accordingly, determining the comprehensive crack feature data based on the initial crack feature data and the target crack feature data includes: Based on the one-to-one correspondence between the initial crack feature data and the target crack feature data, the target crack feature data and the corresponding initial crack feature data are sequentially subjected to difference processing to obtain multiple sets of difference processing results. The results of multiple sets of difference processing are used as comprehensive crack feature data.

2. The method according to claim 1, characterized in that, The energy-storage repeated fracturing method, which involves temporarily plugging the fracture opening before energy storage and then fracturing again, includes: Fracturing fluid carrying a temporary sealant is injected into the target core sample to temporarily seal the initial fracture opening of the target core sample. The amount of the temporary sealant is determined based on the initial fracture characteristic data of the target core sample. An energy storage medium carrying a first tracer is injected into the target core sample to store energy. The first tracer is used to mark the damage cracks formed during the energy storage process. After damage and fractures occur, fracturing fluid carrying a second tracer is injected into the target core sample for repeated fracturing. The second tracer is used to mark the fracturing fractures formed during the repeated fracturing process. After the fracturing fracture is formed, the energy storage is stopped and repeated fracturing is carried out.

3. The method according to claim 2, characterized in that, The initial fracture characteristic data of the target core sample includes the initial fracture width and initial fracture height. Correspondingly, the amount of the temporary plugging agent is determined based on the initial fracture characteristic data of the target core sample, including: Based on the initial crack height and the initial crack width, the amount of temporary sealant used to seal the crack opening is determined according to the following formula: in, This refers to the amount of temporary sealant used for the seam opening; This represents the initial crack height. This represents the initial crack width; The proportion of the embedded crack; The thickness of the filter cake used for compaction after temporary plugging; The apparent density of the temporary sealant for the seam opening; , It is a fixed constant.

4. The method according to claim 1, characterized in that, The method further includes: Different energy storage conditions were selected to carry out repeated fracturing with different energy storage methods under different energy storage conditions. The energy storage conditions included energy storage time, injection rate, and energy storage cycles. Determine the target fracture characteristic data of fracturing fractures formed by repeated fracturing under different energy storage conditions and methods; By comparing the target fracture feature data of fracturing fractures formed by different methods of energy storage repeated fracturing under different energy storage conditions, the target energy storage repeated fracturing method is selected from the comparison results.

5. A device for determining a repetitive energy storage fracturing mode, characterized in that, include: The repeated fracturing module is used to perform energy-storing repeated fracturing on a sealed target core sample in different ways, wherein the target core sample has initial fracture characteristic data; The extraction module is used to identify the fracture zone of the target core sample after repeated energy storage fracturing in different ways and extract the target fracture feature data of the fracture zone. The determination module is used to determine comprehensive fracture characteristic data based on initial fracture characteristic data and target fracture characteristic data. The comprehensive fracture characteristic data is used to determine the fracturing effect of different energy storage repeated fracturing methods. The selection module is used to compare comprehensive fracture characteristic data and select the target energy storage repeated fracturing method based on the comparison results; The device further includes: Obtain a target core sample, which is a core sample containing initial fractures formed after hydraulic fracturing; Steel balls are laid on the initial fractures of the target core sample, and the size of the steel balls is determined based on the initial fracture characteristic data. The target core sample after steel balls are laid is sealed to form a sealed target core sample. The different methods of energy-storage repeated fracturing include energy-storage repeated fracturing before fracturing, energy-storage repeated fracturing after temporary plugging of the fracture opening and then fracturing, and energy-storage repeated fracturing after temporary plugging of the fracture opening and then energy-storage repeated fracturing. Correspondingly, the different methods of energy-storage repeated fracturing on the sealed target core sample include: The sealed target core sample was subjected to repeated fracturing with energy storage followed by fracturing, repeated fracturing with energy storage followed by temporary plugging of the fracture opening and then fracturing, and repeated fracturing with energy storage followed by temporary plugging of the fracture opening and then energy storage and then fracturing. The target fracture feature data includes the fracturing fracture deflection angle. Correspondingly, determining the fracture zone of the target core sample after repeated energy storage fracturing using different methods and extracting the target fracture feature data of the fracture zone includes: The target core samples after repeated fracturing using different energy storage methods were scanned sequentially to obtain multiple sets of three-dimensional images; According to the preset grayscale threshold, the corresponding crack area is extracted from multiple sets of three-dimensional images in sequence; Identify the crack surface in the crack zone and convert the corresponding binarized image of the crack surface into a point cloud dataset; Select adjacent point cloud data from the point cloud dataset and calculate the crack surface normal vector based on the adjacent point cloud data; Obtain the direction of maximum principal stress, and then calculate the fracturing fracture deflection angle based on the fracture surface normal vector and the direction of maximum principal stress. The initial crack feature data and the target crack feature data have a one-to-one correspondence. Accordingly, determining the comprehensive crack feature data based on the initial crack feature data and the target crack feature data includes: Based on the one-to-one correspondence between the initial crack feature data and the target crack feature data, the target crack feature data and the corresponding initial crack feature data are sequentially subjected to difference processing to obtain multiple sets of difference processing results. The results of multiple sets of difference processing are used as comprehensive crack feature data.

6. An electronic device, characterized in that, The method includes a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to implement the steps of the method according to any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that, It stores computer instructions that, when executed by a processor, implement the steps of the method according to any one of claims 1 to 4.

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