Pulse gas-liquid combined fracturing method and device, storage medium and equipment

Abstract

The application discloses a kind of based on pulse gas-liquid complex fracturing method and device, storage medium, equipment, it is related to coal seam mining technical field, main purpose is to solve the problem of low effectiveness of existing soft low-permeability coal seam fracturing.It mainly includes gas fracturing control parameters adjusted according to real-time feedback, controls pulse gas generator to carry out gas fracturing on target operation area in three-stage independent ignition pulse mode, to form main fracture network;According to the real-time fracturing data after main fracture network formation, at least one weak response zone of hydraulic fracturing control parameter and hydraulic fracturing control parameter of weak response zone are identified, and jet flow device is controlled with hydraulic fracturing control parameter, to carry out directional hydraulic fracturing to weak response zone of fracturing, to form secondary fracture network;After completing hydraulic fracturing to weak response zone of fracturing, control injection valve group and support mixed agent are injected into main fracture network and secondary fracture network.It is mainly used for fracturing to coal seam.

Description

Technical Field

[0001] This invention relates to the field of coal seam mining technology, and in particular to a fracturing method and apparatus, storage medium, and equipment based on pulsed gas-liquid composite fracturing. Background Technology

[0002] Most coal seams in my country are characterized by low permeability, high gas content, and complex geological structures. In particular, soft, low-permeability coal seams have extremely low original permeability coefficients, resulting in poor and long-term effects of conventional borehole pre-drainage of gas, which seriously restricts safe and efficient coal mine production and coalbed methane resource recovery.

[0003] Currently, existing methods for improving coal seam permeability mainly include hydraulic fracturing and gas-phase fracturing. However, these two methods are only effective in hard, permeable coal seams. For soft, low-permeability, and highly heterogeneous coal seams, direct use of pure hydraulic fracturing can easily lead to water lock and cause significant damage to soft coal; direct use of pure gas fracturing results in simple fractures and low fracturing effectiveness, thus failing to improve permeability.

[0004] Existing coal seam fracturing generally adopts a construction mode based on static geological models and empirical pumping curves. The injection process mainly relies on macroscopic indicators such as total flow rate and total pressure at the surface for adjustment. Due to the significant heterogeneity of underground coal seams, it is impossible to perceive and respond to the dynamic fracture characteristics of coal and rock in real time. This leads to a mismatch between the pumping program and the actual needs of the formation, resulting in inaccurate adjustment of fracturing parameters and insufficient precision in injection pressure and flow rate control. Summary of the Invention

[0005] In view of this, the present invention provides a fracturing method and apparatus, storage medium and equipment based on pulsed gas-liquid composite fracturing, the main purpose of which is to solve the problem of low fracturing effectiveness in soft and low-permeability coal seams.

[0006] According to one aspect of the present invention, a fracturing method based on pulsed gas-liquid composite is provided, comprising:

[0007] Based on real-time feedback and adjusted gas fracturing control parameters, the pulse gas generator is controlled to perform gas fracturing on the target operating area in a three-stage independent ignition pulse mode, so as to form a main fracture network in the target operating area.

[0008] Based on real-time fracturing data after the formation of the main fracture network, at least one weak fracturing response zone and hydraulic fracturing control parameters of the weak fracturing response zone are identified, and the jet is controlled with the hydraulic fracturing control parameters to perform directional hydraulic fracturing on the weak fracturing response zone in order to form a secondary fracture network on the basis of the main fracture network.

[0009] After hydraulic fracturing of the weak response zone is completed, the proppant mixture is injected into the primary fracture network and the secondary fracture network by controlling the injection valve assembly to complete the fracturing of the target operating area.

[0010] Furthermore, the step of controlling the pulse gas generator to perform gas fracturing on the target operating area in a three-stage independent ignition pulse mode, based on the gas fracturing control parameters adjusted in real time feedback, includes:

[0011] Control the pulse gas generator to perform gas fracturing on the target operating area according to the initialized gas fracturing control parameters;

[0012] During gas fracturing, microseismic parameters and acoustic parameters are collected in real time. Based on the microseismic parameters and acoustic parameters, the gas fracturing control parameters are calculated and updated in real time. The pulse gas generator is then controlled to perform gas fracturing on the target operating area according to the updated gas fracturing control parameters.

[0013] Furthermore, the gas fracturing control parameters include primary ignition pressure, secondary ignition pressure, tertiary holding time, primary and secondary ignition timing interval, and secondary and tertiary ignition timing interval; the micro-vibration parameters include micro-vibration event frequency and micro-vibration magnitude; and the acoustic parameters include acoustic signal continuity and acoustic intensity.

[0014] The calculation process for the gas fracturing control parameters includes:

[0015] The primary ignition pressure is calculated based on the frequency and magnitude of the microseismic events.

[0016] The secondary ignition pressure is calculated based on the sound wave intensity.

[0017] The three-stage pressure holding time is calculated based on the continuity of the acoustic signal.

[0018] The timing intervals for primary and secondary ignition are calculated based on the frequency of micro-vibration events, and the timing intervals for secondary and tertiary ignition are calculated based on the continuity of the acoustic signal.

[0019] Furthermore, the step of identifying at least one weak fracturing response zone and the hydraulic fracturing control parameters of the weak fracturing response zone based on real-time fracturing data after the formation of the main fracture network includes:

[0020] Using the K-nearest neighbor matching model, the target geological conditions corresponding to the real-time fracturing data are identified from the fracturing parameter benchmark library, and the target benchmark fracturing parameters under the target geological conditions are extracted. The real-time fracturing data includes the real-time fracturing parameters corresponding to multiple monitoring areas.

[0021] For each monitoring area, the deviation value between any parameter in the real-time fracturing parameters and the corresponding parameter in the target benchmark fracturing parameters is calculated, and the fracture development status of the monitoring area is determined based on the deviation value continuously monitored within a preset historical period. The fracture development status includes well-developed fractures, no effective fractures, and poorly developed fractures.

[0022] The weak response zone of the fracturing is determined based on the monitoring area with no effective cracks or poor crack development, and the coordinates of the weak response zone are determined based on the coordinate extreme values ​​of all microseismic events within the weak response zone.

[0023] Real-time jet control parameters of the weak response zone are calculated based on the real-time fracturing parameters within the weak response zone, and hydraulic fracturing control parameters are generated based on the coordinates of the weak response zone and the real-time jet control parameters.

[0024] Further, the crack development status of the monitoring area is determined based on the deviation values ​​continuously monitored within a preset historical period, including:

[0025] For each monitoring area, count the number of parameter items whose deviation values ​​are greater than the corresponding deviation threshold within the preset historical time period;

[0026] If the number of the parameter items is greater than the first preset number threshold, then the crack development status of the monitored area is determined to be no effective cracks;

[0027] If the number of the parameter items is less than or equal to the first preset number threshold and greater than the second preset number threshold, then the crack development status of the monitored area is determined to be poor crack development.

[0028] If the quantity is less than or equal to the second preset quantity threshold, then the crack development status of the monitored area is determined to be good crack development.

[0029] Furthermore, the real-time fracturing parameters include acoustic intensity and microseismic event frequency;

[0030] The calculation of real-time jet control parameters for the weak response zone based on real-time fracturing parameters within the weak response zone includes:

[0031] Calculate the difference between the preset acoustic intensity blind zone threshold and the acoustic intensity, calculate the cavitation jet pressure compensation value based on the acoustic intensity difference, and correct the current cavitation jet pressure based on the cavitation jet pressure compensation value to obtain the corrected cavitation jet pressure.

[0032] Calculate the frequency difference between the preset microseismic event frequency blind zone threshold and the microseismic event frequency, calculate the cavitation jet frequency compensation value based on the frequency difference, and correct the current cavitation jet frequency based on the cavitation jet frequency compensation value to obtain the corrected cavitation jet frequency.

[0033] Real-time jet control parameters are generated based on the corrected cavitation jet pressure and the corrected cavitation jet frequency.

[0034] Further, the step of injecting the support mixture into the primary fracture network and the secondary fracture network by controlling the injection valve assembly to complete the fracturing of the target operating area includes:

[0035] After completing the hydraulic fracturing of the weak response zone, real-time fracture morphology data is acquired.

[0036] Based on the target geological conditions and the real-time fracture morphology data, the proppant mixture ratio is matched from the proppant mixture database, and the control parameters of each valve in the proppant mixture group are determined according to the proppant mixture ratio.

[0037] The proppant mixture includes gas, a proppant-containing sand-carrying liquid, and a surfactant; each valve in the injection valve assembly is used to control the injection volume of the high-pressure gas supply component, the high-pressure water pump, the sand-mixing component, and the chemical additive injection pump.

[0038] According to another aspect of the present invention, a fracturing device based on pulsed gas-liquid composite is provided, comprising:

[0039] The pulse gas generator control module is used to control the pulse gas generator to perform gas fracturing on the target operating area in a three-stage independent ignition pulse mode based on the gas fracturing control parameters adjusted by real-time feedback, so as to form a main fracture network in the target operating area.

[0040] The jet ejector control module is used to identify at least one weak response zone and hydraulic fracturing control parameters of the weak response zone based on real-time fracturing data after the formation of the main fracture network, and to control the jet ejector with the hydraulic fracturing control parameters to perform directional hydraulic fracturing on the weak response zone in order to form a secondary fracture network on the basis of the main fracture network.

[0041] The injection valve assembly control module is used to inject the proppant mixture into the primary fracture network and the secondary fracture network by controlling the injection valve assembly after hydraulic fracturing of the weak response zone, so as to complete the fracturing of the target operating area.

[0042] Furthermore, the pulse gas generator control module includes:

[0043] The first fracturing control unit is used to control the pulse gas generator to perform gas fracturing on the target operating area according to the initialized gas fracturing control parameters;

[0044] The second fracturing control unit is used to collect microseismic parameters and acoustic parameters in real time during the gas fracturing process, calculate and update the gas fracturing control parameters in real time based on the microseismic parameters and acoustic parameters, and control the pulse gas generator to perform gas fracturing on the target operating area according to the updated gas fracturing control parameters.

[0045] Furthermore, the gas fracturing control parameters include primary ignition pressure, secondary ignition pressure, tertiary holding time, primary and secondary ignition timing interval, and secondary and tertiary ignition timing interval; the micro-vibration parameters include micro-vibration event frequency and micro-vibration magnitude; and the acoustic parameters include acoustic signal continuity and acoustic intensity.

[0046] In specific application scenarios, the second fracturing control unit is specifically used to calculate the first-stage ignition pressure based on the frequency and magnitude of the microseismic events; calculate the second-stage ignition pressure based on the acoustic wave intensity; calculate the third-stage pressure holding time based on the continuity of the acoustic wave signal; calculate the first-stage and second-stage ignition timing interval based on the frequency of the microseismic events; and calculate the second-stage and third-stage ignition timing interval based on the continuity of the acoustic wave signal.

[0047] Furthermore, the jet injector control module includes:

[0048] The extraction unit is used to identify the target geological conditions corresponding to the real-time fracturing data from the fracturing parameter benchmark library through the K-nearest neighbor matching model, and extract the target benchmark fracturing parameters under the target geological conditions, wherein the real-time fracturing data includes real-time fracturing parameters corresponding to multiple monitoring areas.

[0049] The calculation unit is used to calculate the deviation value between any parameter item in the real-time fracturing parameters and the corresponding parameter item in the target reference fracturing parameters for each monitoring area, and to determine the fracture development status of the monitoring area based on the deviation value continuously monitored within a preset historical period. The fracture development status includes well-developed fractures, no effective fractures, and poorly developed fractures.

[0050] The determination unit is used to determine the weak response zone of the fracturing based on the monitoring area with no effective cracks or poor crack development, and to determine the coordinates of the weak response zone of the fracturing based on the coordinate extreme values ​​of all microseismic events in the weak response zone of the fracturing.

[0051] The generation unit is used to calculate the real-time jet control parameters of the weak response zone based on the real-time fracturing parameters within the weak response zone, and to generate hydraulic fracturing control parameters based on the coordinates of the weak response zone and the real-time jet control parameters.

[0052] Furthermore, in specific application scenarios, the determining unit is specifically used to count the number of parameter items whose deviation values ​​are greater than the corresponding deviation threshold within the preset historical time period for each monitoring area;

[0053] If the number of the parameter items is greater than the first preset number threshold, then the crack development status of the monitored area is determined to be no effective cracks;

[0054] If the number of the parameter items is less than or equal to the first preset number threshold and greater than the second preset number threshold, then the crack development status of the monitored area is determined to be poor crack development.

[0055] If the quantity is less than or equal to the second preset quantity threshold, then the crack development status of the monitored area is determined to be good crack development.

[0056] Furthermore, the real-time fracturing parameters include acoustic intensity and microseismic event frequency;

[0057] In a specific application scenario, the generation unit is specifically used to calculate the difference between the preset acoustic intensity blind zone threshold and the acoustic intensity, calculate the cavitation jet pressure compensation value based on the acoustic intensity difference, and correct the current cavitation jet pressure based on the cavitation jet pressure compensation value to obtain the corrected cavitation jet pressure.

[0058] Calculate the frequency difference between the preset microseismic event frequency blind zone threshold and the microseismic event frequency, calculate the cavitation jet frequency compensation value based on the frequency difference, and correct the current cavitation jet frequency based on the cavitation jet frequency compensation value to obtain the corrected cavitation jet frequency.

[0059] Real-time jet control parameters are generated based on the corrected cavitation jet pressure and the corrected cavitation jet frequency.

[0060] Furthermore, the dispensing valve group control module includes:

[0061] The acquisition unit is used to acquire real-time fracture morphology data after hydraulic fracturing of the weak response zone is completed.

[0062] The matching unit is used to match the proppant mixture ratio from the injection combination database based on the target geological conditions and the real-time fracture morphology data, and to determine the control parameters of each valve body in the injection valve group according to the proppant mixture ratio.

[0063] The proppant mixture includes gas, a proppant-containing sand-carrying liquid, and a surfactant; each valve in the injection valve assembly is used to control the injection volume of the high-pressure gas supply component, the high-pressure water pump, the sand-mixing component, and the chemical additive injection pump.

[0064] According to another aspect of the present invention, a storage medium is provided, wherein at least one executable instruction is stored therein, the executable instruction causing a processor to perform operations corresponding to the above-described pulse-based gas-liquid fracturing method.

[0065] According to another aspect of the present invention, a device is provided, comprising: a multi-source monitoring sensor, a pulse gas generator, an ejector, a dispensing valve assembly, a processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other via the communication bus; the multi-source monitoring sensor, the pulse gas generator, the ejector, and the dispensing valve assembly communicate with the processor via the communication interface;

[0066] The memory is used to store at least one executable instruction, which causes the processor to perform the operations corresponding to the above-described pulse gas-liquid composite fracturing method.

[0067] By employing the above-described technical solutions, the technical solutions provided by the embodiments of the present invention have at least the following advantages:

[0068] This invention provides a fracturing method, apparatus, storage medium, and equipment based on pulsed gas-liquid composite fracturing. In this embodiment, based on real-time feedback-adjusted gas fracturing control parameters, a pulsed gas generator is controlled to perform gas fracturing on a target operating area using a three-stage independent ignition pulse mode, forming a primary fracture network in the target operating area. Based on real-time fracturing data after the formation of the primary fracture network, at least one weak-response zone and its hydraulic fracturing control parameters are identified. The hydraulic fracturing control parameters are then used to control an ejector to perform directional hydraulic fracturing on the weak-response zone, forming a secondary fracture network based on the primary fracture network. After completing the hydraulic fracturing of the weak-response zone, a proppant mixture is injected into the primary and secondary fracture networks by controlling an injection valve assembly, thus completing the fracturing of the target operating area. It enables real-time adjustment of injection pressure and flow rate of different fracturing media to ensure the uniformity of the fracturing injection process. In areas of coal seam with uneven fracture distribution or poor fracture connection, it strengthens the directional treatment of the area to ensure stable fracture propagation, improve and form a complex three-dimensional fracture network, thereby enhancing fracturing effectiveness.

[0069] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the specification. Furthermore, in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0070] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0071] Figure 1 A flowchart of a fracturing method based on pulsed gas-liquid composite provided by an embodiment of the present invention is shown;

[0072] Figure 2 This diagram illustrates a primary crack network and a secondary crack network provided in an embodiment of the present invention.

[0073] Figure 3 A flowchart of a real-time feedback control method for a pulse gas generator provided by an embodiment of the present invention is shown;

[0074] Figure 4 A block diagram of a fracturing device based on pulsed gas-liquid composite is shown in an embodiment of the present invention.

[0075] Figure 5 A schematic diagram of the structure of a device provided in an embodiment of the present invention is shown. Detailed Implementation

[0076] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0077] To address the problem of low effectiveness of existing fracturing methods for soft, low-permeability coal seams, this invention provides a pulsed gas-liquid composite fracturing method. This method uses virtual functional modules within a pulsed gas-liquid composite fracturing device to control corresponding components in the fracturing equipment to perform the corresponding fracturing operations. This fracturing equipment includes multi-source monitoring sensors, a pulsed gas generator, an ejector, a dispensing valve group, a processor, a memory, a communication interface, and a communication bus. The multi-source monitoring sensors are sensors that monitor in real time data such as temperature changes within the coal seam, acoustic signals of fracture propagation, microseismic events, and image information during the fracturing process. Since temperature changes reflect the stress state of the coal seam; acoustic and microseismic signals reveal the fracture initiation point, propagation direction, and distribution density; and image sensors provide the specific morphology and development trend of the fractures, data such as the temperature field, acoustic signals, microseismic events, and fracture morphology can be determined based on this multi-source data. The pulsed gas generator is a controllable pulsed gas generator capable of generating multi-level gas pulse waves ranging from low-frequency high-energy to high-frequency oscillations according to preset pulse frequencies, peak pressures, and pressure durations. The jet injector can be a self-excited oscillating cavitation jet injector, with an internally designed oscillating chamber that modulates continuous water flow into a high-frequency, periodic pulsating jet, generating a cavitation effect to strip and propagate coal and rock fractures. The injection valve assembly is command-controlled and used to switch and mix fracturing media from different pipelines, such as gas, water, proppant-carrying fluid, and chemical permeation enhancers, to form gas fracturing injection, hydraulic fracturing injection, or proppant-carrying fluid injection. The pipelines include those connected to the pulse gas generator, jet injector, proppant mixing device, and chemical additive injection pump, respectively. For example... Figure 1 As shown, the method includes:

[0078] 101. Based on the gas fracturing control parameters adjusted in real time, the pulse gas generator is controlled to perform gas fracturing on the target operating area in a three-stage independent ignition pulse mode to form a main fracture network in the target operating area.

[0079] In this embodiment of the invention, before fracturing begins, boreholes are drilled in the area to be mined. The execution unit of the fracturing equipment is then lowered through the boreholes into the target coal seam and sealed, allowing for subsequent fracturing operations. The target operating area is the area accessible to the fracturing equipment's execution unit after it has been lowered into the target coal seam. The first step in the fracturing process is to pressurize the gas using a pulse gas generator within the equipment. Throughout the fracturing control process, the processor of the equipment, which can be an industrial computer within the ground control system, is responsible for data processing and control. The pulse gas generator employs a three-stage independent ignition pulse mode to perform gas fracturing on the target operating area. Specifically, the gas fracturing control parameters include control parameters corresponding to three sequentially executed levels of gas pulse waves. The first stage uses low-energy pulses to loosen the rock structure, the second stage uses medium-energy pulses to propagate the initial fractures, and the third stage implements high-energy impacts to form the main fracture network.

[0080] It should be noted that the gas fracturing control parameters are dynamically adjusted in real time based on feedback during the gas pressure process. Initially, the system operates according to a set of preset values, and subsequently, the frequency, peak pressure, and duration of each gas pulse are dynamically adjusted based on the geological characteristics of the coal seam and real-time feedback data. Specifically, this can be dynamically optimized using a proportional-integral-derivative control algorithm to ensure that the shock wave creates an effective stress superposition effect within the rock strata.

[0081] 102. Based on the real-time fracturing data after the formation of the main fracture network, identify at least one weak fracturing response zone and the hydraulic fracturing control parameters of the weak fracturing response zone, and control the jet injector to perform directional hydraulic fracturing on the weak fracturing response zone according to the hydraulic fracturing control parameters, so as to form a secondary fracture network on the basis of the main fracture network.

[0082] In this embodiment of the invention, after the main fracture network is formed, hydraulic fracturing is not performed blindly. Instead, real-time fracturing data is first collected using multi-source monitoring sensors, such as distributed fiber optic sensors and downhole microseismic arrays, to identify weak response zones. Then, targeted directional hydraulic fracturing is performed on these weak response zones. The weak response zone refers to an area in the main fracture network formed by gas pulse fracturing that lacks effective fracture development (permeability enhancement blind zone) or has poor fracture development due to lithological heterogeneity, interference from natural fractures, or stress shielding effects. The weak response zone directly reflects the shortcomings in the overall permeability of the coal seam and is a key area for further hydraulic fracturing. Directional fracturing involves automatically adjusting the jet angle based on the relative orientation of the weak response zone and the borehole, achieving targeted fracturing of the weak response zone.

[0083] It should be noted that this application superimposes hydraulic fracturing after the formation of the primary fracture network, which can add a secondary fracture network on the basis of the traditional primary fracture network, such as... Figure 2As shown, hydraulic fracturing can effectively extend and branch the main fracture generated by gas fracturing, improving fracturing quality. Before hydraulic fracturing, identifying fracturing bottleneck areas and performing directional fracturing on these bottleneck areas can avoid ineffective fracturing, thereby improving the accuracy and energy utilization of hydraulic fracturing.

[0084] 103. After hydraulic fracturing of the weak response zone, the proppant mixture is injected into the primary fracture network and the secondary fracture network by controlling the injection valve group to complete the fracturing of the target operating area.

[0085] In this embodiment of the invention, after the fracture network has fully expanded, the primary fracture network and secondary fracture network have been formed. Further, the gas-liquid microbubble proppant-carrying fluid is injected into the fracture network for support by adjusting the injection valve group. The ratio of gas-liquid microbubble proppant-carrying fluid can be adjusted by controlling the on / off state of the valves connecting the various pipelines in the injection valve group. In gas extraction applications, after support is completed, the seal can be released, the previously deployed fracturing equipment can be withdrawn, and the borehole can be connected to the gas extraction pipeline network for long-term gas extraction. The criteria for determining sufficient fracture network expansion can be: detecting any fracture width W ≥ 2mm, any fracture length L ≥ 8m, and microseismic event frequency F = 1.2 times / second, with all deviations within the corresponding preset range. Only then will the ground control system issue a command to the injection valve group to inject the mixture of gas, proppant-containing proppant-carrying fluid, and trace amounts of surfactant into the fracture in a slug-like manner. The gas forms microbubbles in the liquid, which not only reduces the fluid column pressure and facilitates fracture extension but also carries proppant into deeper fracture branches. The surfactant can reduce the interfacial tension between coal and water, thus mitigating the water-locking effect.

[0086] It should be noted that the above process achieves the coupling of three mechanisms: gas shock wave fracturing, hydraulic pulsating cavitation fracturing, and gas-liquid microbubble sand-carrying, forming a complete permeability-enhancing chain of impact-propagation-support. Especially for soft, low-permeability, and highly heterogeneous coal seams, it can avoid the water-locking and soft coal damage of pure hydraulic fracturing, as well as the single-fracture problem of pure gas fracturing; it forms a complex and uniform three-dimensional fracture network, significantly improving coal seam permeability and providing effective protection for safe coal mine production and efficient coalbed methane recovery.

[0087] In one embodiment of the present invention, for further illustration and limitation, such as Figure 3 The real-time feedback control method for the pulse gas generator shown includes the following steps: Based on the gas fracturing control parameters adjusted by real-time feedback, the pulse gas generator is controlled to perform gas fracturing on the target operating area in a three-stage independent ignition pulse mode, including:

[0088] 201. Control the pulse gas generator to perform gas fracturing on the target operating area according to the initialized gas fracturing control parameters.

[0089] 202. During the gas fracturing process, microseismic parameters and acoustic parameters are collected in real time, and the gas fracturing control parameters are calculated and updated in real time based on the microseismic parameters and acoustic parameters. The pulse gas generator is then controlled to perform gas fracturing on the target operating area according to the updated gas fracturing control parameters.

[0090] In this embodiment of the invention, a set of gas fracturing control parameters is initialized based on the geomechanical characteristics of the target coal seam. This initialization parameter set includes, but is not limited to, the pulse frequency, peak pressure, and holding time of each ignition stage, as well as the time interval between each stage. After initialization, a controllable pulse gas generator is controlled to perform the first round of gas fracturing according to this initial parameter set, in order to establish initial fractures and obtain the basic response characteristics of the coal seam.

[0091] After the fracturing operation begins, the real-time dynamic adjustment of gas fracturing control parameters enters the stage. A multi-source monitoring sensor network deployed downhole includes distributed fiber optic temperature and acoustic sensing units, a microseismic monitoring array, and a borehole panoramic camera probe. It acquires and transmits microseismic and acoustic parameters at high frequencies, such as twice per second. Specifically, the microseismic sensors are responsible for acquiring microseismic parameters, including the real-time frequency, magnitude, and spatial distribution coordinates of microseismic events; the acoustic sensing units monitor the acoustic parameters of the fracturing borehole and fractures in real time, including the continuity and intensity of the acoustic signal.

[0092] Furthermore, the system continuously calculates gas fracturing control parameters based on real-time feedback of microseismic parameters and acoustic signal continuity. These newly calculated parameters are then used to update the gas fracturing control parameters in operation, achieving feedback adjustment. By establishing a real-time feedback closed loop, the system changes the traditional open-loop operation mode of gas fracturing, which uses fixed or preset programs. It senses the coal seam's response to each pulse in real time and optimizes and adjusts the next action parameters based on the response characteristics. This collectively adjusts the timing, sequence, and duration of fracturing energy delivery, improving the accuracy and effectiveness of fracturing operations and avoiding ineffective energy dissipation.

[0093] In one embodiment of the present invention, for further explanation and limitation, the calculation process of the gas fracturing control parameters includes:

[0094] The primary ignition pressure is calculated based on the frequency and magnitude of the microseismic events.

[0095] The secondary ignition pressure is calculated based on the sound wave intensity.

[0096] The three-stage pressure holding time is calculated based on the continuity of the acoustic signal.

[0097] The timing intervals for primary and secondary ignition are calculated based on the frequency of microseismic events, and the timing intervals for secondary and tertiary ignition are calculated based on the continuity of acoustic signals.

[0098] In this embodiment of the invention, the gas fracturing control parameters include primary ignition pressure, secondary ignition pressure, tertiary holding time, primary and secondary ignition timing interval, and secondary and tertiary ignition timing interval. Microseismic parameters include microseismic event frequency, microseismic magnitude, and acoustic wave intensity. The main purpose of primary ignition is to initially loosen the coal seam; the energy required is closely related to the initial fracturing difficulty of the coal seam. Therefore, the primary ignition pressure... Calculations are performed based on the real-time collected microseismic event frequency F and microseismic magnitude M. Specifically, ignition in the first quarter is achieved through a low-energy igniter with an ignition energy of 5-10 J and an output pressure of... ;in, This is a proportionality coefficient, which can be set to 0.8 MPa / (cycles / second). (Level). When F < 0.5 times / second or M < Level 2, the ignition energy is automatically increased to 10J. The upper limit is 1 times the coal seam fracturing pressure.

[0099] Secondary ignition is achieved using a medium-energy igniter with an ignition energy of 15-20 J, used to expand the initial fracture generated by primary ignition. At this stage, the activity and extent of fracture expansion can be effectively assessed by the intensity S of the acoustic waves generated during fracturing. A strong acoustic wave intensity indicates active fracture expansion and intense frictional sliding, potentially allowing expansion to be maintained without excessively high pressure; conversely, a weak intensity necessitates increased pressure. Therefore, the secondary ignition pressure... The calculation is mainly related to the real-time sound wave intensity S, and the calculation formula is expressed as: ;in, The proportionality coefficient is set to 0.2 MPa / dB. When S < 65dB, the ignition energy increases to 20J. The upper limit is 0.8 times the coal seam fracturing pressure. Primary ignition and secondary ignition occur at the initial fracturing and preliminary fracture propagation stages, respectively. Therefore, the duration of primary and secondary ignition can be set based on empirical values.

[0100] Three-stage ignition is achieved using a high-energy igniter with an ignition energy of 25-30J. The high-pressure gas needs to be maintained for a certain time to allow for deep wedging and full expansion of the crack. The most direct feedback on whether the pressure holding time is sufficient is the increase in the continuity C of the acoustic signal. When a significant increase in the continuity of the acoustic signal is detected, the pressure holding time should be extended. Therefore, the three-stage pressure holding time... Based on the continuity C of the real-time monitored acoustic signal, it is calculated as follows: ;in, This represents the proportionality coefficient, with a value of 0.1 sec / %. When C < 60%, the ignition energy increases to 30 J. The lower limit is 5 seconds. The value of the third-stage ignition pressure can be calculated using the same formula as the second-stage ignition pressure.

[0101] After obtaining the ignition pressure and holding time for each stage, the timing intervals between stages are further optimized to enhance the synergistic superposition effect of the pressure waves. First and second stage ignition timing intervals. The adjustment is primarily based on the frequency F of the microseismic events. A high microseismic frequency indicates a rapid coal body response and fast stress wave attenuation; therefore, the interval needs to be appropriately shortened to capture the optimal superposition opportunity. ;in, This indicates the deviation between the ignition energy boost frequency threshold and the current micro-vibration event frequency. The ignition energy boost frequency threshold is a preset micro-vibration event frequency threshold used to automatically increase the ignition energy to 10J during the first-stage ignition process. When the frequency is less than this value, the energy is boosted, and this value can be 0.5 times / second. This is due to the timing interval between the second and third-stage ignition... It is related to the continuity C of the sound wave signal. Therefore, the calculation formula is expressed as: ; This represents the deviation between the ignition energy boost acoustic intensity threshold and the current acoustic intensity. The ignition energy boost acoustic intensity threshold is the acoustic intensity determination value when the ignition energy is increased to 20J during the secondary ignition process. When it is less than this value, the energy is boosted, and its value can be 65dB. The above calculation process... and The values ​​are dimensionless and units are not considered.

[0102] By performing targeted, decoupled correlation calculations between different real-time monitored microseismic parameters and the continuity of acoustic signals with different parameters in the gas fracturing control parameters, refined and phased control of the fracturing process is achieved. This ensures that each pulse is activated at the most suitable pressure and time, and maintains the most suitable duration, allowing the fracturing parameters to dynamically adapt to the complex and variable underground coal and rock response, thereby improving the efficiency of fracture initiation and propagation and reducing network complexity.

[0103] In one embodiment of the present invention, for further explanation and limitation, based on real-time fracturing data after the formation of the main fracture network, at least one weak fracturing response zone and hydraulic fracturing control parameters of the weak fracturing response zone are identified, including:

[0104] Using the K-nearest neighbor matching model, the target geological conditions corresponding to the real-time fracturing data are identified from the fracturing parameter benchmark library, and the target benchmark fracturing parameters under the target geological conditions are extracted.

[0105] For each monitoring area, the deviation value between any parameter in the real-time fracturing parameters and the corresponding parameter in the target benchmark fracturing parameters is calculated, and the fracture development status of the monitoring area is determined based on the deviation value continuously monitored within a preset historical period.

[0106] The weak response zone of the fracturing is determined based on the monitoring area with poor crack development, and the coordinates of the weak response zone are determined based on the coordinate extreme values ​​of all microseismic events within the weak response zone.

[0107] Real-time jet control parameters of the weak response zone are calculated based on the real-time fracturing parameters within the weak response zone, and hydraulic fracturing control parameters are generated based on the coordinates of the weak response zone and the real-time jet control parameters.

[0108] The real-time fracturing data includes real-time fracturing parameters corresponding to multiple monitoring areas. These parameters are derived from real-time data acquired by downhole distributed fiber optic sensors and microseismic arrays, and are divided into spatial grid units, with each unit area representing a monitoring area and corresponding to a set of real-time fracturing parameters. Real-time fracturing parameters include, but are not limited to: average acoustic intensity, cumulative frequency of microseismic events, average magnitude of microseismic events, temperature variation, fracture length, and fracture width within the corresponding monitoring area. It should be noted that although this application aims to address the low fracturing effectiveness under the geological condition of soft, low-permeability coal seams, this method still shows good results under other geological conditions, meaning it is widely applicable to fracturing coal seams with different geological conditions. Since the geological conditions of the coal seam are uncertain during fracturing, it is necessary to determine the current geological conditions using real-time fracturing data.

[0109] In this embodiment of the invention, the deviation between the measured values ​​of different parameters in real-time fracturing data and the benchmark values ​​is used as the criterion for determining whether the corresponding monitoring area is a weak fracturing response zone. Weak fracturing response zones include permeability-enhancing blind zones and poorly developed fracture zones. First, a rapid search and matching is performed in a pre-constructed fracturing parameter benchmark library based on the K-nearest neighbor matching model to identify the geological condition type that best matches the current working condition, and the benchmark parameter values ​​under this condition are extracted as the reference standard for the current parameters. Here, K=5, meaning that the five sets of benchmark fracturing parameters most similar to the real-time fracturing data in the benchmark database are selected for similarity matching. The benchmark library stores a large number of standard parameter sets corresponding to high-quality fracture networks formed under different target geological conditions, such as medium-hard high-gas coal seams and soft low-permeability coal seams, i.e., target benchmark fracturing parameters. Then, for each monitoring area, the deviation between each parameter and the benchmark value is calculated item by item. The changes in these deviation values ​​are continuously tracked over a preset time period, such as 10 seconds. If one or more parameters of a monitoring area consistently and significantly deviate from the ideal baseline value over multiple consecutive sampling periods, such as weak acoustic intensity or sparse microseismic activity, it indicates that the area has a poor response to gas fracturing, with no or poorly developed fractures. The fracture development status of this area is then determined to be either no effective fractures or poorly developed fractures. All monitoring areas marked as poorly developed fractures will be initially identified as potential areas, and the spatial relationships of these poorly developed areas will be further analyzed. If multiple poorly developed areas are spatially adjacent or connected, they will be merged into a continuous poorly developed fracture zone. That is, if multiple poorly developed fracture monitoring areas are connected, the area covered by the connected poorly developed fracture monitoring areas will be considered a poorly developed fracture zone. Similarly, the area covered by connected monitoring areas without effective fractures will be considered an anti-permeability blind zone. After identifying the weak fracturing response zone, the three-dimensional coordinate data of microseismic events in the weak fracturing response zone are extracted. For any weak fracturing response zone, the boundary coordinates of the current weak fracturing response zone are determined based on the extreme values ​​of the three-dimensional coordinates (X_j, Y_j, Z_j) of all microseismic events within the blind zone. Left boundary X_min=min(X_j), right boundary X_max=max(X_j), upper boundary Z_max=max(Z_j), lower boundary Z_min=min(Z_j), positioning error ≤1m.

[0110] In one embodiment of the present invention, for further explanation and limitation, determining the crack development status of the monitoring area based on the deviation value continuously monitored within a preset historical time period includes:

[0111] For each monitoring area, count the number of parameter items whose deviation values ​​are greater than the corresponding deviation threshold within the preset historical time period;

[0112] If the number of the parameter items is greater than the first preset number threshold, then the crack development status of the monitored area is determined to be no effective cracks;

[0113] If the number of the parameter items is less than or equal to the first preset number threshold and greater than the second preset number threshold, then the crack development status of the monitored area is determined to be poor crack development.

[0114] If the quantity is less than or equal to the second preset quantity threshold, then the crack development status of the monitored area is determined to be good crack development.

[0115] In this embodiment of the invention, to finely classify the fracture development state, for each independent monitoring area, the deviation values ​​of various real-time fracturing parameters are continuously monitored and statistically analyzed within a preset historical time period, such as a continuous 5 seconds. These parameters include coal seam temperature under stress, acoustic signal continuity, acoustic intensity, microseismic time frequency, microseismic magnitude, fracture width, and fracture length. The number of parameters whose real-time values ​​differ from the baseline values ​​within this time period, i.e., the deviation values ​​that consistently exceed their respective preset deviation thresholds, is statistically analyzed. The deviation thresholds for different parameters can be: coal seam temperature deviation threshold ±3℃ under normal stress, acoustic intensity deviation threshold ±15dB, acoustic signal continuity deviation threshold ±20%, microseismic event frequency deviation threshold ±0.5 times / second, microseismic magnitude deviation threshold ±1 level, fracture width deviation threshold ±0.5mm, and fracture length deviation threshold ±2m.

[0116] Furthermore, the number of parameter deviations exceeding the standard is compared with the first and second preset thresholds to precisely classify the fracture development status into three levels. If the number of parameter deviations exceeding the standard is greater than the first preset threshold (e.g., set to 6), it indicates that the region deviates significantly from the ideal state in most key indicators, showing virtually no response to fracturing energy. The status can be determined as having no effective fractures, and this monitoring area can be marked as an enhanced permeability blind zone. If the number of parameter deviations exceeding the standard is less than or equal to the first preset threshold but greater than the second preset threshold (e.g., set to 2), it indicates that some indicators in the region respond poorly. Although fractures have initiated, their propagation is insufficient and their morphology is substandard. The status is determined as poor fracture development. If the number of deviations exceeding the standard is less than or equal to the second preset threshold, it is determined as good fracture development.

[0117] It should be noted that by introducing two quantitative thresholds, the assessment of gas fracturing effectiveness is transformed from a qualitative judgment to a quantitative classification. The ambiguous concept of defect is decomposed into two precisely distinguishable state levels: completely ineffective and partially unsatisfactory. This allows for targeted calculation of hydraulic fracturing control parameters for different state levels during subsequent directional hydraulic fracturing in the weak-response zone, improving fracturing accuracy. Through the temporal progression of gas fracturing, hydraulic fracturing, and fracture support, as well as the spatial positioning of the weak-response zone, deep coupling of temporal and spatial aspects during fracturing is achieved, ensuring orderly and precise energy input. The temporal progression ensures that different energy forms act in the optimal order, allowing coal seam fractures to be optimally treated at the appropriate time; the weak-response zone ensures the spatial uniformity and effectiveness of energy input, making the coal seam fracture network more complex and uniform. This enables the creation of a large-scale, uniform, and deeply complex three-dimensional fracture network in soft, low-permeability coal seams, significantly improving coal seam permeability and providing strong support for efficient coalbed methane recovery.

[0118] In one embodiment of the present invention, for further explanation and limitation, the calculation of real-time jet control parameters of the weak response zone based on real-time fracturing parameters within the weak response zone includes:

[0119] Calculate the difference between the preset acoustic intensity blind zone threshold and the acoustic intensity, calculate the cavitation jet pressure compensation value based on the acoustic intensity difference, and correct the current cavitation jet pressure based on the cavitation jet pressure compensation value to obtain the corrected cavitation jet pressure.

[0120] Calculate the frequency difference between the preset microseismic event frequency blind zone threshold and the microseismic event frequency, calculate the cavitation jet frequency compensation value based on the frequency difference, and correct the current cavitation jet frequency based on the cavitation jet frequency compensation value to obtain the corrected cavitation jet frequency.

[0121] Real-time jet control parameters are generated based on the corrected cavitation jet pressure and the corrected cavitation jet frequency.

[0122] Real-time fracturing parameters include acoustic intensity and microseismic event frequency. After identifying the weak response zone in fracturing, hydraulic fracturing parameters matching the current real-time state need to be generated. In this embodiment of the invention, real-time jet control parameters are dynamically calculated based on the real-time feedback parameters within the weak response zone, namely acoustic intensity and microseismic event frequency. Specifically, this includes jet pressure compensation calculation and jet frequency compensation calculation.

[0123] The jet pressure compensation calculation process includes: calculating the acoustic intensity difference, which is the difference between the preset acoustic intensity blind zone threshold and the acoustic intensity in the real-time fracturing parameters. This difference reflects the degree to which the acoustic signal in this area deviates from the critical state of the blind zone. This difference is positive, and the larger the value, the more sluggish the response of this area to energy excitation, and the denser or more stressed the rock may be. The preset acoustic intensity blind zone threshold is determined based on engineering test data from soft, low-permeability coal seams. When the acoustic intensity is below 65 dB, there is basically no effective fracture propagation in the coal seam; therefore, 65 dB is set as the critical value for determining the weak response zone of fracturing. The product of this acoustic intensity difference and the cavitation jet pressure adjustment ratio coefficient (unit: MPa / dB) is then used as the cavitation jet pressure compensation value. This cavitation jet pressure adjustment ratio coefficient is preferably 0.3, which is calibrated through fracturing tests on soft, low-permeability coal seams. For every 1 dB decrease in acoustic intensity, the cavitation jet pressure needs to be increased by 0.3 MPa to enhance the hydraulic impact effect and promote fracture propagation. Taking a preset acoustic intensity blind zone threshold of 65dB and an acoustic intensity of 60dB as an example, the cavitation jet pressure compensation value Δp = 0.3 × (65-60) = 1.5MPa, so the cavitation jet pressure is adjusted from 18MPa to 19.5MPa.

[0124] The jet frequency compensation calculation process includes: calculating the frequency difference, i.e., the difference between the preset acoustic intensity blind zone threshold and the acoustic intensity. This difference reflects the degree to which the microseismic activity in the region deviates from the critical state of the blind zone. The preset acoustic intensity blind zone threshold is determined based on engineering test data of soft, low-permeability coal seams. When the microseismic event frequency is below 0.5 times / second, the coal seam basically does not generate new fractures. Therefore, 0.5 times / second is set as the critical value of the microseismic frequency for determining the weak response zone of fracturing. Furthermore, the product of this frequency difference and the cavitation jet frequency adjustment ratio coefficient (preferably 2Hz / (times / second)) is used as the cavitation jet frequency compensation value. The cavitation jet frequency adjustment ratio coefficient is calibrated through fracturing tests of soft, low-permeability coal seams. For every 0.1 times / second decrease in the microseismic frequency, the cavitation jet frequency needs to be increased by 0.2Hz to enhance the pulsating impact effect and induce secondary fractures. Taking a microseismic event frequency of 0.3 times / second as an example, the cavitation jet frequency compensation value Δf = 2 × (0.5 - 0.3) = 0.4 Hz, so the cavitation jet frequency is adjusted from 30 Hz to 30.4 Hz.

[0125] In one embodiment of the invention, for further explanation and definition, controlling the injection valve assembly to inject the support mixture into the primary fracture network and the secondary fracture network to complete the fracturing of the target operating area includes:

[0126] After completing the hydraulic fracturing of the weak response zone, real-time fracture morphology data is acquired.

[0127] Based on the target geological conditions and the real-time fracture morphology data, the proppant mixture ratio is matched from the proppant mixture database, and the control parameters of each valve in the proppant mixture group are determined according to the proppant mixture ratio.

[0128] In this embodiment of the invention, after directional hydraulic fracturing of the weak-response zone, the process enters the fracture propping stage, where a suitable proppant mixture is precisely injected into the formed primary and secondary fracture networks to maintain the long-term conductivity of the coal seam. The proppant mixture includes gas, proppant-containing carrying fluid, and surfactant. The target geological conditions, such as soft, low-permeability coal seams, and real-time fracture morphology data collected and fed back by multi-source monitoring sensors are used as inputs to query a pre-constructed proppant mixture database. This database stores optimized proppant mixture ratios for different combinations of geological conditions and fracture morphologies. The optimized proppant mixture ratio can be obtained through experiments or field verification. After determining the ratio, the control parameters of the corresponding valves in the proppant mixture valve group are determined based on the ratio to control each valve in the valve group. The control valve group is used to control the injection parameters of the high-pressure gas supply component, high-pressure water pump, sand mixing component, and chemical additive injection pump. The layout of the high-pressure gas supply component, high-pressure water pump, sand mixing component, and chemical additive injection pump is controlled aboveground by the surface control system processor.

[0129] The logic for switching pipelines based on the injection valve group includes: after receiving the fracturing stage command, switching to the target pipeline after a delay of ≤0.5 seconds, with the switching sequence being: first closing the current pipeline, waiting for pressure stabilization for 0.2 seconds, and then opening the target pipeline to avoid media mixing and impact. Designed for the characteristics of soft, low-permeability, and highly heterogeneous coal seams, gas fracturing avoids water pressure damage, while hydraulic fracturing reduces damage to soft coal through high-frequency pulsation. Gas-liquid microbubbles carrying sand and fluid alleviate the water-locking effect, avoiding the water-sensitive damage of traditional hydraulic fracturing and the single fracture morphology defect of gas-phase fracturing.

[0130] It should be noted that the aforementioned injection valve assembly, in addition to controlling the injection of proppant, can also be used to control gas fracturing and hydraulic fracturing. During the control of gas fracturing and hydraulic fracturing, the high-pressure gas supply device is connected to one branch of the injection valve assembly's pipeline, and the output side of this branch is connected to a pulse gas generator; the high-pressure water pump is connected to another branch of the injection valve assembly's pipeline, and the output side of this branch is connected to an ejector. During the dynamic adjustment of gas fracturing control parameters or hydraulic fracturing control parameters, the flow rate adjustment of the corresponding valve body is mainly achieved through a stepper motor built into the valve assembly, which controls the valve core opening based on the target flow rate and the linear relationship between the opening and the flow rate. For example, for every 10% increase in opening, the flow rate increases by 1 m³ / h), with an adjustment accuracy of ±0.1 m³ / h. The target flow rate can be the sum of the current baseline flow rate and the adjustment amount calculated during the dynamic adjustment process.

[0131] In one application example, the real-time fracturing parameters for any given moment include: real-time temperature T=28℃, acoustic intensity S=60dB, acoustic signal continuity C=70%, microseismic event frequency F=0.3 times / second, microseismic magnitude M=2, fracture width W=1.2mm, and fracture length L=5m; the reference parameter set for soft, low-permeability coal seams includes: =25℃ =80dB, C0=80%, = 1 time / second =Level 3 =2mm =8m; Calculated deviation values: ΔT=3℃ (reaching threshold), ΔS=20dB (exceeding threshold), ΔC=10% (not exceeding), ΔF=0.7 times / second (exceeding threshold), ΔM=Level 1 (reaching threshold), ΔW=0.8mm (exceeding threshold), ΔL=3m (exceeding threshold). Judgment result: 6 out of 7 indicators exceeded or reached the threshold, lasting for 4 seconds. The judgment status is no effective crack, marked as an anti-reflection blind zone. Calibrated blind zone coordinates: X_min=5m, X_max=8m, Z_min=10m, Z_max=13m. ΔP=0.3×(65-60)=1.5MPa (cavitation jet pressure adjusted from 18MPa to 19.5MPa), Δf=2×(0.5-0.3)=0.4Hz (frequency adjusted from 30Hz to 30.4Hz), synchronously linking the injection valve group to directionally increase the water injection flow in the blind area to ensure precise reinforcement.

[0132] Furthermore, the fracturing equipment employs a dual-backup wired and wireless communication mode with the downhole fracturing execution unit. The wired mode uses armored composite cables for high-speed data transmission, while the wireless mode serves as a backup to ensure continuous communication under harsh operating conditions. The equipment is also equipped with an overpressure alarm component that links in real-time with the downhole pressure sensor. When the downhole pressure exceeds the set pressure threshold, an audible and visual alarm is immediately triggered, and the output of the high-pressure pump unit and gas supply device is automatically cut off to prevent equipment damage or excessive coal fracturing.

[0133] This invention provides a pulsed gas-liquid composite fracturing method. In this embodiment, based on real-time feedback-adjusted gas fracturing control parameters, a pulsed gas generator is controlled to perform gas fracturing in a three-stage independent ignition pulse mode on the target operating area, forming a primary fracture network. Based on real-time fracturing data after the primary fracture network is formed, at least one weak-response zone and its hydraulic fracturing control parameters are identified. The hydraulic fracturing control parameters are then used to control an ejector to perform directional hydraulic fracturing on the weak-response zone, forming a secondary fracture network based on the primary fracture network. After hydraulic fracturing of the weak-response zone, a proppant mixture is injected into the primary and secondary fracture networks by controlling the injection valve assembly, completing the fracturing of the target operating area. This method achieves real-time adjustment of the injection pressure and flow rate of different fracturing media to ensure the uniformity of the fracturing injection process. Furthermore, in areas of uneven fracture distribution or poor fracture connectivity in the coal seam, directional treatment is strengthened in these areas to ensure stable fracture propagation, improve and form a complex three-dimensional fracture network, thereby enhancing fracturing effectiveness. Experiments have shown that by forming a three-dimensional fracture network with wide coverage, high density, and strong stability, coal seam permeability can be increased by 10-20 times, gas extraction concentration can be increased by more than 50%, extraction purity can be increased by 2-3 times, and extraction time to meet standards can be shortened by 35%-40%. At the same time, the modular design of the system reduces equipment maintenance costs, and the standardization of operation procedures reduces human error, significantly improving the economy and reliability of safe production in coal mines.

[0134] Furthermore, as a response to the above Figure 1 The implementation of the method shown in this invention provides a fracturing device based on pulsed gas-liquid composite fracturing, such as... Figure 4 As shown, the device includes:

[0135] The pulse gas generator control module 31 is used to control the pulse gas generator to perform gas fracturing on the target operating area in a three-stage independent ignition pulse mode based on the gas fracturing control parameters adjusted by real-time feedback, so as to form a main fracture network in the target operating area.

[0136] The jet ejector control module 32 is used to identify at least one weak response zone and hydraulic fracturing control parameters of the weak response zone based on real-time fracturing data after the formation of the main fracture network, and to control the jet ejector with the hydraulic fracturing control parameters to perform directional hydraulic fracturing on the weak response zone in order to form a secondary fracture network on the basis of the main fracture network.

[0137] The injection valve group control module 33 is used to inject the proppant mixture into the main fracture network and the secondary fracture network by controlling the injection valve group after hydraulic fracturing of the weak response zone is completed, so as to complete the fracturing of the target operating area.

[0138] Furthermore, the pulse gas generator control module 31 includes:

[0139] The first fracturing control unit is used to control the pulse gas generator to perform gas fracturing on the target operating area according to the initialized gas fracturing control parameters;

[0140] The second fracturing control unit is used to collect microseismic parameters and acoustic parameters in real time during the gas fracturing process, calculate and update the gas fracturing control parameters in real time based on the microseismic parameters and acoustic parameters, and control the pulse gas generator to perform gas fracturing on the target operating area according to the updated gas fracturing control parameters.

[0141] Furthermore, the gas fracturing control parameters include primary ignition pressure, secondary ignition pressure, tertiary holding time, primary and secondary ignition timing interval, and secondary and tertiary ignition timing interval; the micro-vibration parameters include micro-vibration event frequency and micro-vibration magnitude; and the acoustic parameters include acoustic signal continuity and acoustic intensity.

[0142] In specific application scenarios, the second fracturing control unit is specifically used to calculate the first-stage ignition pressure based on the frequency and magnitude of the microseismic events; calculate the second-stage ignition pressure based on the acoustic wave intensity; calculate the third-stage pressure holding time based on the continuity of the acoustic wave signal; calculate the first-stage and second-stage ignition timing interval based on the frequency of the microseismic events; and calculate the second-stage and third-stage ignition timing interval based on the continuity of the acoustic wave signal.

[0143] Furthermore, the jet ejector control module 32 includes:

[0144] The extraction unit is used to identify the target geological conditions corresponding to the real-time fracturing data from the fracturing parameter benchmark library through the K-nearest neighbor matching model, and extract the target benchmark fracturing parameters under the target geological conditions, wherein the real-time fracturing data includes real-time fracturing parameters corresponding to multiple monitoring areas.

[0145] The calculation unit is used to calculate the deviation value between any parameter item in the real-time fracturing parameters and the corresponding parameter item in the target reference fracturing parameters for each monitoring area, and to determine the fracture development status of the monitoring area based on the deviation value continuously monitored within a preset historical period. The fracture development status includes well-developed fractures, no effective fractures, and poorly developed fractures.

[0146] The determination unit is used to determine the weak response zone of the fracturing based on the monitoring area with no effective cracks or poor crack development, and to determine the coordinates of the weak response zone of the fracturing based on the coordinate extreme values ​​of all microseismic events in the weak response zone of the fracturing.

[0147] The generation unit is used to calculate the real-time jet control parameters of the weak response zone based on the real-time fracturing parameters within the weak response zone, and to generate hydraulic fracturing control parameters based on the coordinates of the weak response zone and the real-time jet control parameters.

[0148] Furthermore, in specific application scenarios, the determining unit is specifically used to count the number of parameter items whose deviation values ​​are greater than the corresponding deviation threshold within the preset historical time period for each monitoring area;

[0149] If the number of the parameter items is greater than the first preset number threshold, then the crack development status of the monitored area is determined to be no effective cracks;

[0150] If the number of the parameter items is less than or equal to the first preset number threshold and greater than the second preset number threshold, then the crack development status of the monitored area is determined to be poor crack development.

[0151] If the quantity is less than or equal to the second preset quantity threshold, then the crack development status of the monitored area is determined to be good crack development.

[0152] Furthermore, the real-time fracturing parameters include acoustic intensity and microseismic event frequency;

[0153] In a specific application scenario, the generation unit is specifically used to calculate the difference between the preset acoustic intensity blind zone threshold and the acoustic intensity, calculate the cavitation jet pressure compensation value based on the acoustic intensity difference, and correct the current cavitation jet pressure based on the cavitation jet pressure compensation value to obtain the corrected cavitation jet pressure.

[0154] Calculate the frequency difference between the preset microseismic event frequency blind zone threshold and the microseismic event frequency, calculate the cavitation jet frequency compensation value based on the frequency difference, and correct the current cavitation jet frequency based on the cavitation jet frequency compensation value to obtain the corrected cavitation jet frequency.

[0155] Real-time jet control parameters are generated based on the corrected cavitation jet pressure and the corrected cavitation jet frequency.

[0156] Furthermore, the dispensing valve group control module 33 includes:

[0157] The acquisition unit is used to acquire real-time fracture morphology data after hydraulic fracturing of the weak response zone is completed.

[0158] The matching unit is used to match the proppant mixture ratio from the injection combination database based on the target geological conditions and the real-time fracture morphology data, and to determine the control parameters of each valve body in the injection valve group according to the proppant mixture ratio.

[0159] The proppant mixture includes gas, a proppant-containing sand-carrying liquid, and a surfactant; each valve in the injection valve assembly is used to control the injection volume of the high-pressure gas supply component, the high-pressure water pump, the sand-mixing component, and the chemical additive injection pump.

[0160] This invention provides a pulsed gas-liquid composite fracturing device. In this embodiment, based on real-time feedback-adjusted gas fracturing control parameters, a pulsed gas generator is controlled to perform gas fracturing on the target operating area using a three-stage independent ignition pulse mode, forming a primary fracture network within the target operating area. Based on real-time fracturing data after the formation of the primary fracture network, at least one weak-response zone and its hydraulic fracturing control parameters are identified. The ejector is then controlled using these hydraulic fracturing control parameters to perform directional hydraulic fracturing on the weak-response zone, forming a secondary fracture network based on the primary fracture network. After hydraulic fracturing of the weak-response zone, a proppant mixture is injected into the primary and secondary fracture networks by controlling the injection valve assembly, thus completing the fracturing of the target operating area. This invention achieves real-time adjustment of the injection pressure and flow rate of different fracturing media to ensure the uniformity of the fracturing injection process. Furthermore, in areas of uneven fracture distribution or poor fracture connectivity within the coal seam, directional treatment is strengthened in these areas to ensure stable fracture propagation, improve and form a complex three-dimensional fracture network, thereby enhancing fracturing effectiveness.

[0161] According to one embodiment of the present invention, a storage medium is provided, the storage medium storing at least one executable instruction, the computer-executable instruction being capable of executing the pulse gas-liquid composite fracturing method in any of the above method embodiments.

[0162] Figure 5 The diagram shows a structural schematic of a device according to an embodiment of the present invention. The specific embodiments of the present invention do not limit the specific implementation of the device.

[0163] like Figure 5 As shown, the device may include: a multi-source monitoring sensor 401, a pulse gas generator 403, an ejector 405, a dispensing valve assembly 407, a processor 402, a communication interface 404, a memory 406, and a communication bus 408.

[0164] The processor 402, communication interface 404, and memory 406 communicate with each other via communication bus 408. The multi-source monitoring sensor 401, pulse gas generator 403, jet injector 405, and injection valve group 407 communicate with the processor 402 via communication interface 404. The multi-source monitoring sensor 401, pulse gas generator 403, jet injector 405, and injection valve group 407 together form a downhole execution unit.

[0165] The processor 402 is used to execute program 410, which can specifically execute the relevant steps in the above-described embodiment of the fracturing method based on pulsed gas-liquid composite.

[0166] Specifically, program 410 may include program code that includes computer operation instructions.

[0167] Processor 402 may be a central processing unit (CPU), a specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. The device may include one or more processors of the same type, such as one or more CPUs; or it may include processors of different types, such as one or more CPUs and one or more ASICs.

[0168] Memory 406 is used to store program 410. Memory 406 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0169] Specifically, program 410 can be used to cause processor 402 to perform the following operations:

[0170] Based on real-time feedback and adjusted gas fracturing control parameters, the pulse gas generator is controlled to perform gas fracturing on the target operating area in a three-stage independent ignition pulse mode, so as to form a main fracture network in the target operating area.

[0171] Based on real-time fracturing data after the formation of the main fracture network, at least one weak fracturing response zone and hydraulic fracturing control parameters of the weak fracturing response zone are identified, and the jet is controlled with the hydraulic fracturing control parameters to perform directional hydraulic fracturing on the weak fracturing response zone in order to form a secondary fracture network on the basis of the main fracture network.

[0172] After hydraulic fracturing of the weak response zone is completed, the proppant mixture is injected into the primary fracture network and the secondary fracture network by controlling the injection valve assembly to complete the fracturing of the target operating area.

[0173] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing systems. They can be centralized on a single computing system or distributed across a network of multiple computing systems. Optionally, they can be implemented using program code executable by a computing system, thereby storing them in a storage system for execution by the computing system. In some cases, the steps shown or described can be performed in a different order than those presented herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0174] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A fracturing method based on pulsed gas-liquid composite fracturing, characterized in that, include: Based on real-time feedback and adjusted gas fracturing control parameters, the pulse gas generator is controlled to perform gas fracturing on the target operating area in a three-stage independent ignition pulse mode, so as to form a main fracture network in the target operating area. Based on real-time fracturing data after the formation of the main fracture network, at least one weak fracturing response zone and hydraulic fracturing control parameters of the weak fracturing response zone are identified, and the jet is controlled with the hydraulic fracturing control parameters to perform directional hydraulic fracturing on the weak fracturing response zone in order to form a secondary fracture network on the basis of the main fracture network. After hydraulic fracturing of the weak response zone is completed, the proppant mixture is injected into the primary fracture network and the secondary fracture network by controlling the injection valve group to complete the fracturing of the target operating area. The gas fracturing control parameters, adjusted based on real-time feedback, control the pulse gas generator to perform gas fracturing on the target operating area in a three-stage independent ignition pulse mode, including: The pulse gas generator is controlled to perform gas fracturing on the target operating area according to the initialized gas fracturing control parameters. During the gas fracturing process, micro-vibration parameters and acoustic parameters are collected in real time. The gas fracturing control parameters are calculated and updated in real time based on the micro-vibration parameters and acoustic parameters. The pulse gas generator is then controlled to perform gas fracturing on the target operating area according to the updated gas fracturing control parameters. The gas fracturing control parameters include primary ignition pressure, secondary ignition pressure, tertiary holding time, primary and secondary ignition timing interval, and secondary and tertiary ignition timing interval; the microseismic parameters include microseismic event frequency and microseismic magnitude; the acoustic parameters include acoustic signal continuity and acoustic intensity; the calculation process of the gas fracturing control parameters includes: The primary ignition pressure is calculated based on the frequency and magnitude of the micro-vibration events; the secondary ignition pressure is calculated based on the acoustic wave intensity; the tertiary pressure holding time is calculated based on the continuity of the acoustic wave signal; the primary and secondary ignition timing intervals are calculated based on the frequency of the micro-vibration events, and the secondary and tertiary ignition timing intervals are calculated based on the continuity of the acoustic wave signal.

2. The method according to claim 1, characterized in that, The process of identifying at least one weak fracturing response zone and hydraulic fracturing control parameters for the weak fracturing response zone based on real-time fracturing data after the formation of the main fracture network includes: Using the K-nearest neighbor matching model, the target geological conditions corresponding to the real-time fracturing data are identified from the fracturing parameter benchmark library, and the target benchmark fracturing parameters under the target geological conditions are extracted. The real-time fracturing data includes the real-time fracturing parameters corresponding to multiple monitoring areas. For each monitoring area, the deviation value between any parameter in the real-time fracturing parameters and the corresponding parameter in the target benchmark fracturing parameters is calculated, and the fracture development status of the monitoring area is determined based on the deviation value continuously monitored within a preset historical period. The fracture development status includes well-developed fractures, no effective fractures, and poorly developed fractures. The weak response zone of the fracturing is determined based on the monitoring area with no effective cracks or poor crack development, and the coordinates of the weak response zone are determined based on the coordinate extreme values ​​of all microseismic events within the weak response zone. Real-time jet control parameters of the weak response zone are calculated based on the real-time fracturing parameters within the weak response zone, and hydraulic fracturing control parameters are generated based on the coordinates of the weak response zone and the real-time jet control parameters.

3. The method according to claim 2, characterized in that, Determining the crack development status of the monitoring area based on the deviation values ​​continuously monitored within a preset historical period includes: For each monitoring area, count the number of parameter items whose deviation values ​​are greater than the corresponding deviation threshold within the preset historical time period; If the number of the parameter items is greater than the first preset number threshold, then the crack development status of the monitored area is determined to be no effective cracks; If the number of the parameter items is less than or equal to the first preset number threshold and greater than the second preset number threshold, then the crack development status of the monitored area is determined to be poor crack development. If the quantity is less than or equal to the second preset quantity threshold, then the crack development status of the monitored area is determined to be good crack development.

4. The method according to claim 2, characterized in that, The real-time fracturing parameters include acoustic intensity and microseismic event frequency; The calculation of real-time jet control parameters for the weak response zone based on real-time fracturing parameters within the weak response zone includes: Calculate the difference between the preset acoustic intensity blind zone threshold and the acoustic intensity, calculate the cavitation jet pressure compensation value based on the acoustic intensity difference, and correct the current cavitation jet pressure based on the cavitation jet pressure compensation value to obtain the corrected cavitation jet pressure. Calculate the frequency difference between the preset microseismic event frequency blind zone threshold and the microseismic event frequency, calculate the cavitation jet frequency compensation value based on the frequency difference, and correct the current cavitation jet frequency based on the cavitation jet frequency compensation value to obtain the corrected cavitation jet frequency. Real-time jet control parameters are generated based on the corrected cavitation jet pressure and the corrected cavitation jet frequency.

5. The method according to any one of claims 1-4, characterized in that, The step of injecting the support mixture into the primary fracture network and the secondary fracture network by controlling the injection valve assembly to complete the fracturing of the target operating area includes: After completing the hydraulic fracturing of the weak response zone, real-time fracture morphology data is acquired. Based on the target geological conditions and the real-time fracture morphology data, the proppant mixture ratio is matched from the proppant mixture database, and the control parameters of each valve in the proppant mixture group are determined according to the proppant mixture ratio. The proppant mixture includes gas, a proppant-containing sand-carrying liquid, and a surfactant; each valve in the injection valve assembly is used to control the injection volume of the high-pressure gas supply component, the high-pressure water pump, the sand-mixing component, and the chemical additive injection pump.

6. A fracturing device based on pulsed gas-liquid composite fracturing, the device being used to perform the operation corresponding to the fracturing method based on pulsed gas-liquid composite fracturing as described in claim 1, characterized in that, include: The pulse gas generator control module is used to control the pulse gas generator to perform gas fracturing on the target operating area in a three-stage independent ignition pulse mode based on the gas fracturing control parameters adjusted by real-time feedback, so as to form a main fracture network in the target operating area. The jet ejector control module is used to identify at least one weak response zone and hydraulic fracturing control parameters of the weak response zone based on real-time fracturing data after the formation of the main fracture network, and to control the jet ejector with the hydraulic fracturing control parameters to perform directional hydraulic fracturing on the weak response zone in order to form a secondary fracture network on the basis of the main fracture network. The injection valve assembly control module is used to inject the proppant mixture into the primary fracture network and the secondary fracture network by controlling the injection valve assembly after hydraulic fracturing of the weak response zone, so as to complete the fracturing of the target operating area.

7. A storage medium, characterized in that, The storage medium stores at least one executable instruction that causes the processor to perform the operation corresponding to the pulse gas-liquid composite fracturing method as described in any one of claims 1-5.

8. A fracturing device based on pulsed gas-liquid composite fracturing, characterized in that, include: The system includes a multi-source monitoring sensor, a pulsed gas generator, an ejector, a dispensing valve assembly, a processor, a memory, a communication interface, and a communication bus. The processor, the memory, and the communication interface communicate with each other via the communication bus. The multi-source monitoring sensor, the pulsed gas generator, the ejector, and the dispensing valve assembly communicate with the processor via the communication interface. The memory is used to store at least one executable instruction that causes the processor to perform the operation corresponding to the pulse gas-liquid composite fracturing method as described in any one of claims 1-5.

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