Horizontal well fracturing simulation method, device and equipment and storage medium

Abstract

The invention provides a horizontal well fracturing simulation method, device and equipment and a storage medium, and belongs to the technical field of oil and gas reservoir development. The method comprises the following steps: controlling true triaxial fracturing equipment to pressurize a fracturing test piece through a hydraulic fracturing pump; the crack flow value of each crack is collected through a flowmeter; calculating a flow distribution coefficient of the fracturing test piece based on the fracture flow value, wherein the flow distribution coefficient is used for indicating the stress interference degree between the fractures; and based on the flow distribution coefficient, the morphological characteristics of the crack, the acoustic emission signal and the pumping pressure curve, performing crack stress interference evaluation on the fracturing test piece. According to the method, the real-time non-uniform distribution characteristic of each crack flow in the multi-crack synchronous expansion process can be obtained, the dynamic quantization parameter of the stress interference intensity is increased, in addition, the influence rule of the pressure in the fractured section crack on the expansion of the lower section crack during the multi-crack sequence expansion can be obtained, and the expansion efficiency is improved. And a foundation is laid for mechanical mechanism research of multi-fracture interaction in the horizontal well multi-stage fracturing process.

Description

Technical Field

[0001] This application relates to the technical field of oil and gas reservoir development, and particularly to a horizontal well fracturing simulation method, device, equipment and storage medium. Background Art

[0002] Unconventional oil and gas resources have the characteristic of low permeability, so reservoir stimulation methods such as fracturing are required to achieve industrial exploitation. In recent years, single-well multi-stage multi-cluster and intensive cutting fracturing technologies have been applied to large-scale reservoir stimulation construction on site. The spacing between multiple fracture clusters has been reduced from the original 30 - 60 m to 5 - 15 m, greatly increasing the oil and gas production of unconventional reservoirs. In addition, simultaneous fracturing, zipper fracturing and sequential fracturing have also been proposed between multiple horizontal wells, and the morphology of multiple fractures is more complex. During the single-well multi-stage and multi-well fracturing processes, strong stress interference (stress shadow effect) occurs due to the interaction of multiple fractures, resulting in a decrease in fracture width, fracture distortion and shortening, making the fracturing effect and area less than expected. Therefore, it is necessary to establish an evaluation method for the stress interference intensity of multiple fractures during the multi-stage fracturing process of horizontal wells and obtain the characteristics of the propagation morphology of multiple fractures to effectively guide on-site construction. Summary of the Invention

[0003] This application provides a horizontal well fracturing simulation method, device, equipment and storage medium, which can obtain the real-time non-uniform distribution characteristics of the fracture flow rates of each fracture during the synchronous propagation process of multiple fractures, and improve the accuracy of stress interference analysis. The technical solution is as follows:

[0004] On the one hand, an embodiment of this application provides a horizontal well fracturing simulation method, including:

[0005] Controlling a true triaxial fracturing device to pressurize a fracturing specimen through a hydraulic fracturing pump, where at least two fractures are provided in the fracturing specimen;

[0006] Collecting the fracture flow rate values of each fracture through a flowmeter, where the hydraulic pipelines at different fractures are connected to different flowmeters and then connected to the same hydraulic fracturing pump;

[0007] Calculating a flow distribution coefficient of the fracturing specimen based on the fracture flow rate values, where the flow distribution coefficient is used to indicate the degree of stress interference between fractures;

[0008] Evaluating the fracture stress interference of the fracturing specimen based on the flow distribution coefficient, the morphological characteristics of the fractures, acoustic emission signals and pump pressure curves.

[0009] On the other hand, an embodiment of this application provides a horizontal well fracturing simulation device, including:

[0010] A control module, configured to control a true triaxial fracturing device to pressurize a fracturing specimen through a hydraulic fracturing pump, where at least two fractures are provided in the fracturing specimen;

[0011] A collection module, configured to collect the fracture flow values of each fracture through a flowmeter. Different hydraulic pipelines at different fractures are connected to different flowmeters and then connected to the same hydraulic fracturing pump;

[0012] A calculation module, configured to calculate the flow distribution coefficient of the fracturing specimen based on the fracture flow values. The flow distribution coefficient is used to indicate the stress interference degree between fractures;

[0013] An evaluation module, configured to evaluate the fracture stress interference of the fracturing specimen based on the flow distribution coefficient, the morphological characteristics of the fractures, the acoustic emission signals, and the pump pressure curve.

[0014] On the other hand, an embodiment of the present application provides an electronic device, which includes a memory and a processor; a computer program is stored in the memory, and when the computer program is executed by the processor, the method described in the above aspect is implemented.

[0015] On the other hand, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program, and the computer program is loaded and executed by a processor to implement the method described in the above aspect.

[0016] The technical solution provided by the present application at least includes the following beneficial effects:

[0017] The horizontal well fracturing simulation method, device, equipment, and storage medium provided by the present application provide an indoor simulation method for multi-fracture stress interference in horizontal well multi-stage fracturing on the basis of a true triaxial hydraulic fracturing device, and can obtain the real-time non-uniform distribution characteristics of the flow rates of each fracture during the multi-fracture synchronous propagation process. Furthermore, the flow distribution coefficient, which is a dynamic quantization parameter of the stress interference intensity, is increased. The stress interference law is analyzed based on parameters such as the flow distribution coefficient, the morphological characteristics of the fractures, the acoustic emission signals, and the pump pressure curve, improving the accuracy of stress interference analysis. In addition, the influence law of the pressure in the fractured section on the propagation of the lower fracture during the sequential propagation of multi-fractures can be obtained, laying a foundation for the study of the mechanical mechanism of multi-fracture interaction during the horizontal well multi-stage fracturing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments.

[0019] Figure 1 is a flowchart of a horizontal well fracturing simulation method provided by an exemplary embodiment of the present application;

[0020] Figure 2 is a flowchart of a horizontal well fracturing simulation method provided by another exemplary embodiment of the present application;

[0021] Figure 3 is a flowchart of a horizontal well fracturing simulation method provided by another exemplary embodiment of the present application;

[0022] Figure 4 is a schematic diagram of a horizontal well multi-stage fracturing indoor simulation device provided by an exemplary embodiment of the present application;

[0023] Figure 5 is a schematic diagram of a horizontal well multi-stage fracturing indoor simulation device provided by another exemplary embodiment of the present application;

[0024] Figure 6 is a schematic diagram of single-well segmented multi-cluster fracturing of a horizontal well provided by an exemplary embodiment of the present application;

[0025] Figure 7 is a schematic diagram of multi-stage fracturing of two horizontal wells provided by an exemplary embodiment of the present application;

[0026] Figure 8 is a structural block diagram of a horizontal well fracturing simulation device provided by an exemplary embodiment of the present application;

[0027] Figure 9 is a structural block diagram of an electronic device provided by an exemplary embodiment of the present application. Detailed Embodiments

[0028] To make the objectives, technical solutions, and advantages of the present application clearer, the following will further describe the embodiments of the present application in detail with reference to the accompanying drawings.

[0029] Embodiment 1

[0030] Please refer to Figure 1 , which shows a flowchart of a horizontal well fracturing simulation method provided by an exemplary embodiment of the present application. The method includes the following steps:

[0031] Step 101, control the true triaxial fracturing equipment to pressurize the fracturing specimen through a hydraulic fracturing pump.

[0032] Among them, at least two fractures are provided in the fracturing specimen.

[0033] For indoor simulation experiments of horizontal well multi-stage fracturing, it is required that the fracturing specimen has multiple fractures to simulate the real fracturing environment. In one possible implementation, the equipment controls the slot cutter to cut slots at preset positions in the specimen, or a technician manually cuts the inside of the specimen in advance.

[0034] The true triaxial fracturing equipment pressurizes the fracturing specimen through a hydraulic fracturing pump to simulate the horizontal well fracturing process.

[0035] Optionally, hydraulic pipelines are correspondingly arranged at each crack in the test piece, and all the hydraulic pipelines are connected to the same hydraulic fracturing pump to realize synchronous fracturing of each crack.

[0036] Step 102: Collect the crack flow values of each crack through a flowmeter. Among them, the hydraulic pipelines at different cracks are connected to different flowmeters and then connected to the same hydraulic fracturing pump.

[0037] In a possible implementation manner, the hydraulic pipelines at each crack are respectively connected to their corresponding flowmeters, and multiple hydraulic pipelines are respectively connected to multiple precision flowmeters and then commonly connected to 1 high-precision sensor and the hydraulic fracturing pump to realize real-time measurement of the non-uniform distribution of the flow rates of multiple cracks in a single fracturing stage.

[0038] Step 103: Calculate the flow distribution coefficient of the fracturing test piece based on the crack flow values. The flow distribution coefficient is used to indicate the stress interference degree between cracks.

[0039] The device evaluates the dynamic stress interference characteristics through the non-uniform distribution coefficient of the real-time flow rates of multiple cracks and calculates the flow distribution coefficient of the fracturing test piece. The value of this coefficient changes in real time as the cracks expand. The flow distribution coefficient can indicate the stress interference degree and the flow distribution uniformity between cracks.

[0040] Step 104: Conduct a crack stress interference assessment on the fracturing test piece based on the flow distribution coefficient, the morphological characteristics of the cracks, the acoustic emission signals, and the pump pressure curve.

[0041] The device reveals the multi-crack stress interference mechanism of the synchronous propagation of multiple cracks in a horizontal well based on the flow distribution coefficient, combined with the post-fracture three-dimensional multi-crack morphological characteristics, acoustic emission signals, and pump pressure curve.

[0042] In summary, the horizontal well fracturing simulation method provided by this application, based on the true triaxial hydraulic fracturing device, provides an indoor simulation method for multi-crack stress interference in horizontal well multi-stage fracturing, can obtain the real-time non-uniform distribution characteristics of the flow rates of each crack during the synchronous propagation of multiple cracks, and further increases the dynamic quantification parameter of the stress interference intensity, that is, the flow distribution coefficient. Analyze the stress interference law based on parameters such as the flow distribution coefficient, the morphological characteristics of the cracks, the acoustic emission signals, and the pump pressure curve, improve the accuracy of stress interference analysis, and lay a foundation for the research on the mechanical mechanism of the interaction between multiple cracks during the horizontal well multi-stage fracturing process.

[0043] Embodiment 2

[0044] Please refer to Figure 2 , which shows the flowchart of the horizontal well fracturing simulation method provided by another exemplary embodiment of this application. The method includes the following steps:

[0045] Step 201: Control the true triaxial fracturing equipment to pressurize the fracturing specimen through a hydraulic fracturing pump.

[0046] Step 202: Collect the fracture flow values of each fracture through a flowmeter. Among them, the hydraulic pipelines at different fractures are connected to different flowmeters and then connected to the same hydraulic fracturing pump.

[0047] For the specific implementation manners of Step 201 to Step 202, reference can be made to the above-mentioned Step 101 to Step 102, and the embodiments of the present application will not be elaborated herein.

[0048] Step 203: Obtain the fracture flow values corresponding to adjacent odd-numbered fractures.

[0049] Step 204: Determine the total fracture flow value and the middle fracture flow value of the odd-numbered fractures. The middle fracture flow value is the fracture flow value corresponding to the fracture in the middle among the odd-numbered fractures.

[0050] In the embodiments of the present application, the equipment collects the flow values of adjacent odd-numbered fractures to calculate the flow distribution coefficient. The total fracture flow value is the sum of the fracture flow values of each fracture collected at the same moment.

[0051] Schematically, there are three fractures a, b, and c distributed in the specimen in descending order of depth. The equipment collects the fracture flow value Qa of fracture a, the fracture flow value Qb of fracture b, and the fracture flow value Qc of fracture c through a precision flowmeter, and calculates the total fracture flow value Q total = Qa + Qb + Qc. Then, the flow distribution coefficient is calculated based on Qb and Q total.

[0052] Step 205: Calculate the flow distribution coefficient based on the total fracture flow value and the middle fracture flow value.

[0053] In a possible implementation manner, the calculation formula of the flow distribution coefficient is defined as follows:

[0054] Q middle / Q total - 1 / n

[0055] Wherein, Q middle is the middle fracture flow value, Q total is the total fracture flow value, n is the number of the odd-numbered fractures, and n is a positive odd number.

[0056] Schematically, the flow non-uniform distribution coefficient corresponding to the three fractures a, b, and c in the specimen is Q2 / (Q1 + Q2 + Q3) - 1 / 3, where Q1, Q2, and Q3 are the flow values of the three fractures respectively. The closer the flow non-uniform distribution coefficient is to 0, the more uniform the flow distribution of each fracture is, and the smaller the stress interference between them is.

[0057] Step 206: Evaluate the fracture stress interference of the fracturing specimen based on the flow distribution coefficient, the morphological characteristics of the fractures, the acoustic emission signal, and the pump pressure curve.

[0058] For the specific implementation of step 206, reference may be made to the above step 104, and details are not repeated herein in the embodiments of the present application.

[0059] Embodiment III

[0060] Please refer to Figure 3 , which shows a flowchart of a horizontal well fracturing simulation method provided by another exemplary embodiment of the present application. The method includes the following steps:

[0061] Step 301: Control the true triaxial fracturing equipment to pressurize the fracturing specimen in a preset order through a hydraulic fracturing pump to form hydraulic fractures.

[0062] Among them, different fractures are respectively connected to different hydraulic fracturing pumps through corresponding hydraulic pipelines.

[0063] In the method of the embodiment of the present application, a multi-fracture sequential propagation simulation test can also be carried out using the fracturing specimen. Different from the above synchronous propagation simulation test, in the fracturing specimen of the multi-fracture sequential propagation simulation test, different fractures are respectively connected to different hydraulic fracturing pumps through corresponding hydraulic pipelines, and multiple hydraulic pipelines are respectively connected to multiple high-precision pressure sensors and hydraulic fracturing pumps to realize independent fracture initiation and propagation and fluid pressure loading of each fracture, so as to realize fracture sequential propagation.

[0064] By adjusting the injection displacement of the pump connected to the already fractured section, the equipment can collect different pressure values and fluid pressure in the fracture.

[0065] Step 302: Collect the pump pressure curve and acoustic emission signal of each fracture.

[0066] It is worth noting that step 301 and step 302 are not strictly executed in sequence. For each stage of fracture fracturing in step 301, the equipment immediately executes step 302 to collect the pump pressure curve and acoustic emission signal corresponding to the fracture, and then pressurizes the next stage of fracture.

[0067] In a possible implementation manner, the equipment controls different hydraulic fracturing pumps to pressurize for sequential propagation. Specifically, step 301 includes the following steps:

[0068] Step 301a: Control the true triaxial fracturing equipment to pressurize the i-th fracture channel through the i-th hydraulic fracturing pump to form the i-th hydraulic fracture, where i is a positive integer.

[0069] Step 301b: Set the displacement of the fracturing fluid pumped by the i-th hydraulic fracturing pump and measure the injection pressure of the i-th hydraulic fracturing pump.

[0070] Step 301c: Control the true triaxial fracturing equipment to pressurize the (i + 1)-th fracture channel through the (i + 1)-th hydraulic fracturing pump to form the (i + 1)-th hydraulic fracture.

[0071] In a possible implementation, the equipment sets the displacement of the i-th hydraulic fracturing pump, constantly injects a high-viscosity fracturing fluid with a preset displacement, and measures its injection pressure pi. The average fluid pressure in the fracture can be approximately confirmed as half of the injection pressure, that is, pi / 2.

[0072] Schematically, the hydraulic fracturing pump A fractures the specimen at a given displacement through the hydraulic pipeline a. A hydraulic fracture 1 is formed by fracture propagation at the corresponding position of the fracture channel, and the corresponding pump pressure curve and acoustic emission signal are recorded. The equipment sets the injection displacement of the hydraulic fracturing pump A connecting the hydraulic pipeline a and the already fractured fracture 1, and then the hydraulic fracturing pump B connected to the corresponding position of the fracture channel through the hydraulic pipeline b pumps the fracturing fluid to form a non-planar fracture 2, and its pump pressure curve and acoustic emission signal are recorded. Similarly, after setting the injection displacements of the two corresponding hydraulic fracturing pumps A and B connecting the hydraulic pipelines a and b, the hydraulic fracturing pump C pumps the fracturing fluid through the hydraulic pipeline c to form a non-planar fracture 3, and the corresponding pump pressure curve and acoustic emission signal are recorded.

[0073] Step 303: Determine the law of sequential fracture propagation based on the pump pressure curve, acoustic emission signal, and morphological characteristics of the fractures.

[0074] Based on the above fracturing method, the pressurization of a single hydraulic fracturing pump is used to achieve the propagation of the corresponding first-level fracture. When the next-level fracture propagates, the corresponding fluid pressure in the fracture is obtained by controlling the displacement of the hydraulic fracturing pump corresponding to the already fractured fracture, and the influence law of the already fractured fracture with fluid pressure on the propagation of the next-level fracture can be analyzed. Specifically, a fluid pressure is first applied to the already fractured fracture, and when the next-level fracture propagates, the change in the injection pressure in the already fractured fracture is measured by a high-precision pressure sensor to analyze the law of fracture interaction during sequential fracturing.

[0075] In the embodiment of the present application, based on the true triaxial hydraulic fracturing equipment, a laboratory simulation method for multi-stage fracturing and multi-fracture stress interference in horizontal wells is provided, which can obtain the real-time non-uniform distribution characteristics of the flow rates of each fracture during the synchronous propagation process of multi-fractures, and can simulate the influence law of the upper-level fracture with fluid pressure on the propagation of the next-level fracture during the sequential propagation process of multi-fractures, laying a foundation for the research on the mechanical mechanism of multi-fracture interaction during the multi-stage fracturing process in horizontal wells.

[0076] Optionally, the equipment can also control and change the displacement and viscosity of the fluid pumped by the hydraulic fracturing pump connecting the hydraulic pipelines in the above embodiment, and compare the influence law of the pressure value in the already fractured fracture on the sequential propagation of multi-fractures to more realistically simulate the on-site staged fracturing process. After the above step 303, the following steps can also be included:

[0077] Step 1: Adjust the displacement and viscosity of the fracturing fluid injected by each hydraulic fracturing pump, and record the injection pressure of the hydraulic fracturing pump.

[0078] The equipment adjusts the displacement and viscosity of the fracturing fluid injected by the hydraulic fracturing pump to obtain different injection pressure values. Furthermore, the average fluid pressure of the already opened fracture can be approximately obtained as half of the injection pressure.

[0079] Step 2: Based on the pump pressure curve, acoustic emission signal, and morphological characteristics collected under different in-fracture fluid pressure values of the already opened fractures, determine the influence law of fractures with different fluid pressures on the sequential fracture propagation.

[0080] Example 4

[0081] Optionally, before conducting the fracturing test, it is also necessary to complete the preparation of the fracturing specimen and the connection of the device. The method provided in the embodiment of the present application further includes the following steps before step 101:

[0082] Step 3: Inject a sealing reagent into the pipeline embedded in the fracturing specimen to a preset depth.

[0083] Optionally, a high-strength epoxy resin adhesive can be used as the sealing reagent.

[0084] Before setting the hydraulic pipeline for each fracture, inject the sealing reagent into the pipeline to a preset depth. Among them, the pipeline is a PVC pipeline embedded in the specimen.

[0085] The specimen preparation process includes: collecting underground coal rock or outcrops of the target reservoir to prepare rock specimens, and their sizes can be prepared according to the maximum accommodation size of the true triaxial hydraulic fracturing equipment; using a drill bit to drill a hole with a predetermined depth and diameter, then putting a PVC pipe with an outer diameter smaller than the hole diameter, and slowly injecting high-strength epoxy resin adhesive into the annulus between the hole and the PVC pipe. After placing it for two days to solidify, the hole is fixed; using a slitting cutter to slit through the PVC pipe and the annular epoxy resin adhesive at the predetermined fracture position in the PVC pipe to form n fracture channels connecting the wellbore and the rock, and removing the impurities cut in the PVC pipe.

[0086] Step 4: Control the injection of a preset dose of soluble solid particles into the pipeline so that one fracture is wrapped by the soluble solid particles.

[0087] Optionally, small particle soluble salt can be used as the soluble solid particles.

[0088] Step 5: Control the insertion of a hydraulic pipeline into the soluble solid particles.

[0089] Step 6: Continue to inject the sealing reagent and soluble solid particles until the next crack is wrapped by the soluble solid particles, and control the hydraulic pipeline corresponding to the next crack until the hydraulic pipelines corresponding to all cracks are set up.

[0090] Specifically, control to put small particle soluble salt to wrap the first crack channel, and put the hydraulic pipeline. Slowly inject high-strength epoxy resin glue into the PVC pipe to a height before the position of the predetermined second crack channel to seal the hydraulic pipeline and the PVC pipe. Put salt, bury the hydraulic pipeline and inject resin glue in sequence according to the above steps until the implantation of all the predetermined n cracks and the corresponding n hydraulic pipelines is completed. After completion, inject warm water into the pipeline and invert the specimen to discharge the soluble salt, thus realizing the preparation of the multi-crack channel rock specimen.

[0091] Schematically, Figure 4 Fig. shows a schematic diagram of a simulation device for multi-stage fracturing in a horizontal well. The preparation of the fracturing specimen and the connection process of the device are as follows:

[0092] (1) Use a ring sand wire cutting machine to cut coal rock to prepare a specimen 1 with dimensions of 300mm×300mm×300mm;

[0093] (2) Use a drill bit to drill a hole with a depth of 23.5 cm and a diameter of 2.8 cm in the center. Then, place a PVC pipe 3 with an outer diameter of 2.5 cm, an inner diameter of 2.2 cm, and a length of 23.5 cm in the center (the end is sealed with 2 cm of high-strength resin glue 2), and slowly inject high-strength epoxy resin glue 2 into the annulus between the hole and the PVC pipe and let it solidify for two days to achieve hole sealing;

[0094] (3) Use a slitting device to slit the PVC pipe 3 at 21 cm, 15 cm, and 9 cm (with the wellhead as the origin) to penetrate the PVC pipe and the annulus resin glue 8, 6, 8, and put small particle soluble salt to wrap the crack 4 position (1 cm), and put a hydraulic pipeline 5 with an outer diameter of 8 mm and an inner diameter of 6 mm;

[0095] (4) Slowly inject high-strength epoxy resin glue 2 into the PVC pipe 3 to a length of 15.5 cm to seal the hydraulic pipeline 5 and the PVC pipe 3. After solidification, put 1 cm thick small particle salt and bury a hydraulic pipeline 7 with an outer diameter of 8 mm and an inner diameter of 6 mm;

[0096] (5) Inject high-strength resin glue 2 into the PVC pipe 3 to a length of 9.5 cm, put 1 cm thick salt to wrap 8 and put a hydraulic pipeline 9 with an outer diameter of 8 mm and an inner diameter of 6 mm, and inject epoxy resin 2 into the PVC pipe 3 to the wellhead to seal the hydraulic pipelines 5, 7, and 9. After solidification, inject warm water into the three hydraulic pipelines and invert the specimen to discharge the soluble salt, complete the preparation of the segmented fracturing specimen, and obtain 3 crack channels 4, 6, 8 with a crack spacing of 6 cm.

[0097] use Figure 4 When the specimen shown in the figure is subjected to an indoor simulation experiment, the three hydraulic pipelines 5, 7, and 9 are respectively connected to three independent precision flow meters 10, 11, and 12 and then connected together to a high-precision pressure sensor 13 and a hydraulic fracturing pump 14, which can realize the real-time measurement of the uneven distribution of multi-fracture flow in a single fracturing section and simulate the synchronous expansion process of multiple clusters of fractures in a single section of a horizontal well.

[0098] When multiple fractures are sequentially expanded, the specimen preparation process is the same as that of synchronous expansion. The difference is that in the sequential expansion test, different fractures are connected to different hydraulic fracturing pumps through corresponding hydraulic pipelines. Figure 5 As shown, three hydraulic pipelines 5, 7, and 9 are independently connected to three fracturing sensors 13 and a hydraulic fracturing pump 14 respectively.

[0099] After loading the true triaxial stress, the hydraulic fracturing pump 14 is used to fractur e the specimen at a given displacement through the hydraulic pipeline 5, and the crack expands at the crack channel 4 to form a hydraulic crack 15a, and the corresponding pump pressure curve and acoustic emission signal are recorded; after setting the hydraulic fracturing pump 14 connecting the hydraulic pipeline 5 and the crack a that has been opened to a constant pressure value, the hydraulic fracturing pump 14 connecting the hydraulic pipeline 7 and the crack channel 6 pumps fracturing fluid to form a non-planar crack 15b, and its pump pressure curve and acoustic emission signal are recorded; similarly, two hydraulic fracturing pumps connecting the hydraulic pipelines 5 and 7 are set to After the corresponding hydraulic fracturing pump 14 reaches a constant pressure value, the hydraulic fracturing pump pumps fracturing fluid through the hydraulic pipeline 9 to form a non-planar crack 15c, and records the corresponding pump pressure curve and acoustic emission signal; after the test is completed, the three-dimensional morphology of multiple cracks is scanned, and the sequential expansion law of multiple cracks is obtained by combining the pump pressure curve and the acoustic emission signal; the injection displacement of the hydraulic fracturing pump connecting the hydraulic pipelines 5 and 7 is changed, and after the test is completed, the influence of different injection pressure values ​​of the cracks that have been opened on the sequential expansion of multiple cracks is compared to more realistically simulate the on-site staged fracturing process.

[0100] Optionally, the above-mentioned drilling hole size, PVC pipe size, crack position and number can be adjusted according to test requirements and equipment conditions.

[0101] Optionally, cement casting specimens can be used to carry out horizontal well multi-stage fracturing simulation. First, a PVC pipe for horizontal well multi-stage fracturing is made according to the above steps, eliminating the drilling and annulus resin injection steps, and a 5 mm diameter hole is drilled at a phase angle of 90° at the predetermined position of the fracture and soluble salt is poured out, and the drilled hole is sealed with an A4 paper roll, and the PVC pipe is buried when the artificial cement specimen is cast to prepare the test specimen.

[0102] Optionally, the rock specimens can be composed of different rocks (sandstone, shale, coal rock, etc.) to study the multi-fracture penetration and propagation law of multi-cluster fracturing in multi-layered horizontal wells.

[0103] Optionally, a phosphor is added to the water-based fracturing fluid to mark the multi-fracture morphology after fracturing.

[0104] Optionally, liquid CO2, supercritical CO2, liquid nitrogen, air, etc. can be used for horizontal well multi-stage fracturing simulation. After fracturing is completed, an aqueous solution containing phosphor can be injected at a low pressure (far less than the rock fracture pressure) to mark the multi-fracture morphology after fracturing.

[0105] Optionally, based on the above structure and method, the embodiments of the present application can also conduct horizontal well segmented multi-cluster fracturing simulation tests. Corresponding flow meters, pressure sensors and hydraulic fracturing pumps can be connected to achieve flow distribution measurement of synchronous propagation of multi-fractures in the same segment and simulation of sequential propagation of multi-fractures in different segments. Figure 6 Fig. shows a schematic diagram of single-well segmented multi-cluster fracturing in a horizontal well. 1 is a fracturing specimen. Fractures a, b, c, d, e, f are respectively connected to a hydraulic pressure pump 14 through different flow meters 12 and pressure sensors 13. First, fractures a and b in the first segment are fractured synchronously, then fractures c and d in the next segment are fractured, and finally fractures e and f in the last segment are fractured.

[0106] Optionally, based on the above embodiments, multi-well multi-stage fracturing simulation of at least two horizontal wells can be carried out, including sequential fracturing, zipper fracturing and synchronous fracturing. Among them, sequential fracturing is to fracture the single-well segmented multi-cluster fractures of each well in sequence until all wells are fractured; zipper fracturing is to fracture the first segment fractures of each well in sequence by segment and then fracture the second segment fractures of each well until the end; synchronous fracturing is to fracture the fractures in the same segment of each well simultaneously until all segments of fractures are fractured, that is, fracture the first segment fractures of each well simultaneously and then fracture the second segment fractures until the end. Figure 7 Fig. shows a schematic diagram of multi-stage fracturing of two horizontal wells.

[0107] Embodiment 5

[0108] Please refer to Figure 8 , which shows a structural block diagram of a horizontal well fracturing simulation device provided by an exemplary embodiment of the present application. The device includes:

[0109] A control module 801, configured to control a true triaxial fracturing device to pressurize a fracturing specimen through a hydraulic fracturing pump, where at least two fractures are provided in the fracturing specimen;

[0110] An acquisition module 802, configured to acquire the fracture flow rate values of each fracture through a flow meter, where the hydraulic pipelines at different fractures are connected to different flow meters and then connected to the same hydraulic fracturing pump;

[0111] A calculation module 803, configured to calculate a flow distribution coefficient of the fracturing specimen based on the fracture flow rate values, where the flow distribution coefficient is used to indicate the stress interference degree between fractures;

[0112] An evaluation module 804, configured to perform crack stress interference evaluation on the fracturing specimen based on the flow distribution coefficient, the morphological characteristics of the crack, the acoustic emission signal, and the pump pressure curve.

[0113] Optionally, the calculation module 803 is further configured to:

[0114] Obtain the crack flow values corresponding to adjacent odd-numbered cracks;

[0115] Determine the total crack flow value and the middle crack flow value of the odd-numbered cracks, where the middle crack flow value is the crack flow value corresponding to the crack in the middle of the odd-numbered cracks;

[0116] Calculate the flow distribution coefficient based on the total crack flow value and the middle crack flow value.

[0117] Optionally, the calculation formula of the flow distribution coefficient includes:

[0118] Qmid / Qtotal - 1 / n

[0119] Where Qmid is the middle crack flow value, Qtotal is the total crack flow value, n is the number of odd-numbered cracks, and n is a positive odd number.

[0120] Optionally, the control module 801 is further configured to:

[0121] Control the true triaxial fracturing equipment to pressurize the fracturing specimen in a preset order through a hydraulic fracturing pump to form hydraulic cracks, where different cracks are respectively connected to different hydraulic fracturing pumps through corresponding hydraulic pipelines;

[0122] The acquisition module 802 is further configured to acquire the pump pressure curve and the acoustic emission signal of each crack;

[0123] The evaluation module 804 is further configured to determine the crack order extension law based on the pump pressure curve, the acoustic emission signal, and the morphological characteristics of the crack.

[0124] Optionally, the control module 801 is further configured to:

[0125] Control the true triaxial fracturing equipment to pressurize the i-th crack channel through the i-th hydraulic fracturing pump to form the i-th hydraulic crack, where i is a positive integer;

[0126] Set the displacement of the fracturing fluid injected by the i-th hydraulic fracturing pump, and measure the injection pressure value of the i-th hydraulic fracturing pump;

[0127] Control the true triaxial fracturing equipment to pressurize the (i + 1)-th crack channel through the (i + 1)-th hydraulic fracturing pump to form the (i + 1)-th hydraulic crack.

[0128] Optionally, the evaluation module 804 is further configured to:

[0129] Adjust the displacement and viscosity of the fracturing fluid injected by each hydraulic fracturing pump, and record the injection pressure of the hydraulic fracturing pump;

[0130] Based on the pump pressure curve, the acoustic emission signal, and the morphological characteristics collected under different average in-slot fluid pressure values, determine the influence law of fractures with different fluid pressures on the sequential propagation of fractures.

[0131] Optionally, the device further includes an assembly module, configured to:

[0132] Inject a sealing reagent into the pipeline embedded in the fracturing specimen to a preset depth;

[0133] Control the introduction of a preset dose of dissolvable solid particles into the pipeline so that a fracture is wrapped by the dissolvable solid particles;

[0134] Control the insertion of a hydraulic pipeline into the dissolvable solid particles;

[0135] Continue to inject the sealing reagent and the dissolvable solid particles until the next fracture is wrapped by the dissolvable solid particles, and control the insertion of the hydraulic pipeline corresponding to the next fracture until the hydraulic pipelines corresponding to all fractures are set up.

[0136] Embodiment Six

[0137] An embodiment of the present application provides an electronic device; Figure 9 The following is a schematic structural diagram of the electronic device provided by the embodiment of the present application. As Figure 9 shown, the electronic device 900 includes: a processor 901, at least one communication bus 902, a user interface 903, at least one external communication interface 904, and a memory 905. Among them, the communication bus 902 is configured to enable connection communication between these components. Among them, the user interface 903 may include a display screen, and the external communication interface 904 may include a standard wired interface and a wireless interface. The processor 901 is configured to execute the program of the horizontal well fracturing simulation method stored in the memory to implement the steps in the method provided by the above embodiments.

[0138] An embodiment of the present application further provides a computer-readable storage medium, in which a computer program is stored, and the computer program is loaded and executed by a processor to implement the method as described in the above embodiments.

[0139] The embodiments of the present application also provide a computer program product that runs on a processor of a computer device, enabling the computer device to execute the method described in the above embodiments.

[0140] It should be noted here that the descriptions of the above storage medium, electronic device, and remote control embodiments are similar to those of the above method embodiments and have similar beneficial effects to the method embodiments. For the technical details not disclosed in the storage medium and device embodiments of the present application, please refer to the descriptions of the method embodiments of the present application for understanding.

[0141] It should be understood that the "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures, or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, the "in one embodiment" or "in an embodiment" that appears throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present application, the sequence numbers of the above processes do not mean the order of execution. The execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application. The sequence numbers of the embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0142] It should be noted that in this article, the term "comprising", "including" or any other variation thereof is intended to cover a non-exclusive inclusion, so that a process, method, object or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, object or device. Without further limitation, the element defined by the statement "including a..." does not exclude the existence of other identical elements in the process, method, object or device including the element.

[0143] In several embodiments provided by the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are only illustrative. For example, the division of the units is only a logical function division, and there can be other division methods in actual implementation. For example, multiple units or components can be combined, or can be integrated into another system, or some features can be ignored, or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed with each other can be through some interfaces. The indirect coupling or communication connection of the devices or units can be electrical, mechanical, or other forms.

[0144] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units; they may be located in one place or distributed over multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0145] In addition, in each embodiment of the present application, each functional unit may be all integrated in a processing unit, or each unit may be separately regarded as a unit alone, or two or more units may be integrated in one unit; the above-mentioned integrated units may be implemented in the form of hardware, or in the form of a combination of hardware and software functional units.

[0146] Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions. The foregoing program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps including the above method embodiments; and the foregoing storage medium includes: removable storage devices, read-only memories (ROMs), magnetic disks, or optical disks and other various media that can store program codes.

[0147] Alternatively, if the above-mentioned integrated units of the present application are implemented in the form of software functional modules and sold or used as independent products, they may also be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the embodiments of the present application essentially or the part that contributes to the prior art can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a controller to execute all or part of the methods described in the various embodiments of the present application. And the foregoing storage medium includes: removable storage devices, ROMs, magnetic disks, or optical disks and other various media that can store program codes.

[0148] The above is only the implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A horizontal well fracturing simulation method, characterized in that Including: Controlling a true triaxial fracturing device to pressurize a fracturing specimen through a hydraulic fracturing pump, where at least two cracks are provided in the fracturing specimen; Collecting the crack flow values of each crack through a flowmeter, where the hydraulic pipelines at different cracks are connected to different flowmeters and then connected to the same hydraulic fracturing pump; Calculating the flow distribution coefficient of the fracturing specimen based on the crack flow values, and the flow distribution coefficient is used to indicate the stress interference degree between cracks; Evaluating the crack stress interference of the fracturing specimen based on the flow distribution coefficient, the morphological characteristics of the cracks, acoustic emission signals, and pump pressure curves.

2. The method according to claim 1, characterized in that, The calculating the flow distribution coefficient of the fracturing specimen based on the crack flow values includes: Obtaining the crack flow values corresponding to adjacent odd-numbered cracks; Determining the total crack flow value and the middle crack flow value of the odd-numbered cracks, where the middle crack flow value is the crack flow value corresponding to the crack in the middle of the odd-numbered cracks; Calculating the flow distribution coefficient based on the total crack flow value and the middle crack flow value.

3. The method according to claim 2, wherein The calculation formula of the flow distribution coefficient includes: Qmid / Qtotal - 1 / n Where Qmid is the middle crack flow value, Qtotal is the total crack flow value, n is the number of odd-numbered cracks, and n is a positive odd number.

4. The method according to any one of claims 1 to 3, characterized in that, The method further includes: Controlling the true triaxial fracturing device to pressurize the fracturing specimen through a hydraulic fracturing pump in a preset order to form hydraulic cracks, where different cracks are respectively connected to different hydraulic fracturing pumps through corresponding hydraulic pipelines; Collecting the pump pressure curves and acoustic emission signals of each crack; Determining the crack order propagation law based on the pump pressure curves, the acoustic emission signals, and the morphological characteristics of the cracks.

5. The method according to claim 4, wherein The controlling the true triaxial fracturing device to pressurize the fracturing specimen through a hydraulic fracturing pump in a preset order to form hydraulic cracks includes: Controlling the true triaxial fracturing device to pressurize the ith crack channel through the ith hydraulic fracturing pump to form the ith hydraulic crack, where i is a positive integer; Setting the displacement of the fracturing fluid injected by the ith hydraulic fracturing pump and measuring the injection pressure of the ith hydraulic fracturing pump; Controlling the true triaxial fracturing device to pressurize the (i + 1)th crack channel through the (i + 1)th hydraulic fracturing pump to form the (i + 1)th hydraulic crack.

6. The method according to claim 5, wherein After determining the crack order propagation law based on the pump pressure curves, the acoustic emission signals, and the morphological characteristics of the cracks, the method further includes: Adjusting the displacement and viscosity of the fracturing fluid injected by each hydraulic fracturing pump and recording the injection pressure of the hydraulic fracturing pump; Determining the influence law of cracks with different fluid pressures on the crack order propagation based on the pump pressure curves, the acoustic emission signals, and the morphological characteristics collected under different in-crack fluid pressure values.

7. The method according to any one of claims 1 to 3, characterized in that, Before controlling the true triaxial fracturing device to pressurize the fracturing specimen through a hydraulic fracturing pump, the method further includes: Injecting a sealing reagent into the pipeline embedded in the fracturing specimen to a preset depth; Controlling to put a preset dose of soluble solid particles into the pipeline so that one crack is wrapped by the soluble solid particles; Control a hydraulic pipeline to extend into the soluble solid particles; Continue to inject the sealing reagent and the soluble solid particles until the next crack is wrapped by the soluble solid particles, and control the hydraulic pipeline corresponding to the next crack until the hydraulic pipelines corresponding to all cracks are set up.

8. A horizontal well fracturing simulation device, characterized in that, Comprising: A control module for controlling a true triaxial fracturing device to pressurize a fracturing specimen through a hydraulic fracturing pump, wherein at least two cracks are provided in the fracturing specimen; An acquisition module for acquiring the crack flow values of each crack through a flowmeter, wherein the hydraulic pipelines at different cracks are connected to different flowmeters and then connected to the same hydraulic fracturing pump; A calculation module for calculating a flow distribution coefficient of the fracturing specimen based on the crack flow values, and the flow distribution coefficient is used to indicate the stress interference degree between cracks; An evaluation module for evaluating the crack stress interference of the fracturing specimen based on the flow distribution coefficient, the morphological characteristics of the cracks, the acoustic emission signals and the pump pressure curve.

9. An electronic device, characterized in that, Comprising a memory and a processor; a computer program is stored in the memory, and when the computer program is executed by the processor, the method according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that, A computer program is stored, and the computer program is loaded and executed by a processor to implement the method according to any one of claims 1 to 7.

Images