Hydraulic fracturing pilot test method, electronic equipment, storage medium and program product

Abstract

The invention provides a hydraulic fracturing pilot test method, electronic equipment, a storage medium and a program product, and relates to the technical field of hydraulic fracturing test. The method comprises the following steps: determining a fractured well in a to-be-tested site and a plurality of test wells meeting a preset position relationship with the fractured well; determining the crustal stress state of the target test well; according to the crustal stress state and preset hydraulic fracturing process parameters, fracturing testing is conducted on the fractured well, and collected data of the detection equipment is obtained; based on the rock mass sectioning image of the preset position of the to-be-tested site, crack network characterization information is determined, and the crack network characterization information is used for indicating the shape of a crack formed by fracturing and the distribution condition of a propping agent; according to the collected data, the fracturing test process is inverted, and fracturing dynamic process information is obtained; and generating a hydraulic fracturing process optimization scheme according to a comparison result between the fracturing dynamic process information and the fracture network characterization information. According to the method, the accuracy and practicability of a hydraulic fracturing test result are improved.

Description

Technical Field

[0001] The present application relates to the technical field of hydraulic fracturing testing, and in particular to a hydraulic fracturing pilot testing method, electronic equipment, storage medium and program product. Background Art

[0002] The development of unconventional oil and gas resources has become one of the main growth points of the global energy industry in recent years. With the increasing depletion of traditional oil and gas resources, the development and utilization of unconventional oil and gas resources is particularly important. As the core technology of unconventional oil and gas development, hydraulic fracturing technology can effectively improve the permeability and production capacity of reservoirs and is a key means to achieve economic exploitation of unconventional oil and gas. Hydraulic fracturing increases the oil and gas flow path by forming a complex fracture network in the formation, thereby increasing the oil and gas recovery rate.

[0003] At present, the research on the formation law of hydraulic fracturing network is mainly concentrated in two aspects: laboratory and mine. In laboratory research, small-scale testing technology is usually used to simulate the hydraulic fracturing process. However, there is a large scale gap between these laboratory tests and the cracks in actual construction, and it is impossible to fully simulate the real hydraulic fracturing process. In the mine, the method of coring around the well after fracturing can describe the expansion direction and number of cracks and indicate the opening of the perforation cluster cracks. However, this method can only observe the fracture characteristics in the coring well.

[0004] It can be seen from this that the hydraulic fracturing test results of the prior art, when applied to reservoir operations, have the problems of poor accuracy in characterizing the overall picture of fractures and low practicality. Summary of the invention

[0005] The embodiments of the present application provide a hydraulic fracturing pilot test method, electronic equipment, storage medium and program product to solve the problem that the hydraulic fracturing test results of the prior art are not accurate in representing the overall picture of the fractures and are not practical when applied to reservoir operations.

[0006] In a first aspect, an embodiment of the present application provides a hydraulic fracturing pilot test method, comprising:

[0007] Determine a fracturing well in a site to be tested and a plurality of test wells that satisfy a preset position relationship with the fracturing well, wherein the site to be tested is a site that satisfies the test conditions after lithological analysis of a plurality of test sites at different geographical locations;

[0008] Determining a geostress state of a target test well, wherein a location of the target test well and a location of the fracturing well meet a first distance requirement;

[0009] According to the ground stress state and the preset hydraulic fracturing process parameters, a fracturing test is performed on the fracturing well to obtain the collected data of the detection equipment, wherein the detection equipment is a device pre-deployed in the test site for collecting data during the fracturing process, and the detection equipment includes fracturing equipment, microseismic stations, electromagnetic equipment, acoustic optical fiber, strain optical fiber, and seepage equipment;

[0010] Based on the rock mass section image at the preset location of the test site, the fracture network characterization information is determined, and the fracture network characterization information is used to indicate the fracture morphology and proppant distribution of the fracture formed by the hydraulic fracturing;

[0011] Based on the collected data, the fracturing test process is inverted to obtain the fracturing dynamic process information, which includes the crack formation process, fracturing fluid flow process, formation deformation process, and proppant migration process;

[0012] Based on the comparison results between the fracturing dynamic process information and the fracture network characterization information, a hydraulic fracturing process optimization plan is generated, and the hydraulic fracturing process optimization plan is used to optimize the preset hydraulic fracturing process parameters and hydraulic fracturing steps.

[0013] In a possible implementation, determining a fracturing well in a site to be tested and a plurality of test wells that satisfy a preset position relationship with the fracturing well includes:

[0014] Obtain lithology information of the site to be tested;

[0015] According to the lithology information and the preset drilling design parameters, drilling and coring are carried out in the site to be tested to obtain a fracturing well in the site to be tested and a plurality of test wells that meet the preset position relationship with the fracturing well.

[0016] In a possible implementation, the method further includes:

[0017] Pre-processing the cementing casing to determine the target cementing casing and the state of the target cementing casing to be installed;

[0018] If the to-be-installed status indicates that the target cementing casing meets the installation conditions, the target cementing casing is deployed to the fracturing well;

[0019] According to the preset in-pipe introduction requirements, cementing materials are introduced from the cementing casing to the bottom of the fracturing well, and according to the preset out-pipe introduction requirements, cementing materials are introduced between the cementing casing and the well wall of the fracturing well;

[0020] After the cementing material solidifies, the fracturing well is drilled from the cementing casing until the depth of the fracturing well meets the preset depth, thereby obtaining the cemented fracturing well.

[0021] In a possible implementation, before determining the ground stress state of the target test well, the method further includes:

[0022] Obtain core samples from the fracture well and each test well;

[0023] Conduct bedding structure analysis on all core samples to determine the first test well that meets bedding distribution conditions;

[0024] Deploy the electrodes of the electromagnetic device inside the first test well, and deploy the electrodes of the electromagnetic device for testing formation resistance on the ground where the second test well is located, and the location of the second test well and the location of the fracturing well meet the second distance requirement;

[0025] Deploy the fracturing equipment on the ground at the location of the fracturing well, and connect the connecting pipe of the fracturing equipment to the cementing casing of the fracturing well;

[0026] Deploy microseismic stations on the ground and side facing surfaces of the site to be tested;

[0027] Deploy the acoustic optical fiber from the bottom of the third test well to the ground, and deploy it in the test site based on a preset ground trajectory, wherein the location of the third test well and the location of the fracturing well meet a third distance requirement;

[0028] Deploy the strain optical fiber from the bottom of the first target test well to the surface, and enter the second target test well through the ground between the first target test well and the second target test well, and return to the surface through the second target test well after the strain optical fiber is deployed to the bottom of the second target test well;

[0029] The seepage equipment is deployed at the wellhead of the second test well, and the seepage equipment includes a pressure meter and a flow meter.

[0030] In a possible implementation, a fracturing test is performed on a fracturing well according to the ground stress state and preset hydraulic fracturing process parameters to obtain collected data of the detection equipment, including:

[0031] Determine the injection parameters of the fracturing fluid and the injection parameters of the mixed fluid according to the ground stress state and the preset hydraulic fracturing process parameters, wherein the mixed fluid includes the fracturing fluid and the proppant, the fracturing fluid is the fracturing fluid added with fluorescent powder, and the proppant is the proppant added with the preset dye;

[0032] According to the fracturing fluid injection parameters and the mixed fluid injection parameters, a fracturing test is performed on the fracturing well to obtain the collected data of the detection equipment. The collected data includes the pressure, flow, microseismic event data, formation electromagnetic parameter data, acoustic wave signal, and strain data during the fracturing process.

[0033] In a possible implementation, determining fracture network characterization information based on a rock mass section image at a preset location of a site to be tested includes:

[0034] The rock mass at the preset position of the test site is sectioned to obtain a plurality of sectioned rock masses at different sectioning depths;

[0035] For each sectioned rock mass, an image of a fracture area in the sectioned rock mass is determined based on the light corresponding to the fluorescent powder;

[0036] Determine an image of a proppant region in a sectioned rock mass based on a color of a preset dye;

[0037] Based on the 3D reconstruction method, the rock mass section images corresponding to each sectioned rock mass are superimposed according to the sectioning depth to construct a 3D model;

[0038] The rock mass section image includes a fracture area image and a proppant area image, and the fracture network characterization information is determined by the three-dimensional fracture morphology and proppant distribution in the three-dimensional model.

[0039] In a second aspect, an embodiment of the present application provides a hydraulic fracturing pilot test device, comprising:

[0040] The first determination module is used to determine the fracturing wells in the site to be tested and multiple test wells that meet the preset position relationship with the fracturing wells. The site to be tested is a site that meets the test conditions after lithology analysis of multiple test sites in different geographical locations;

[0041] A first test module, used to determine the ground stress state of a target test well, wherein the location of the target test well and the location of the fracturing well meet a first distance requirement;

[0042] The second test module is used to perform a fracturing test on the fracturing well according to the ground stress state and the preset hydraulic fracturing process parameters to obtain the collected data of the detection equipment, wherein the detection equipment is a device pre-deployed in the site to be tested for collecting data during the fracturing process, and the detection equipment includes a fracturing device, a microseismic station, an electromagnetic device, an acoustic optical fiber, a strain optical fiber, and a seepage device;

[0043] The second determination module is used to determine the fracture network characterization information based on the rock mass section image at the preset position of the test site, and the fracture network characterization information is used to indicate the fracture morphology and proppant distribution of the fracture formed by the hydraulic fracturing;

[0044] The data processing module is used to invert the fracturing test process according to the collected data to obtain the fracturing dynamic process information, which includes the crack formation process, fracturing fluid flow process, formation deformation process, and proppant migration process;

[0045] The generation module is used to generate a hydraulic fracturing process optimization plan based on the comparison results between the fracturing dynamic process information and the fracture network characterization information. The hydraulic fracturing process optimization plan is used to optimize the preset hydraulic fracturing process parameters and hydraulic fracturing steps.

[0046] In a third aspect, an embodiment of the present application provides an electronic device, including: a memory, a processor;

[0047] Memory stores computer-executable instructions;

[0048] The processor executes the computer-executable instructions stored in the memory, so that the processor executes the above first aspect and / or various possible implementations of the first aspect.

[0049] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the first aspect above and / or various possible implementations of the first aspect.

[0050] In a fifth aspect, an embodiment of the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the above first aspect and / or various possible implementation methods of the first aspect.

[0051] The hydraulic fracturing pilot test method, electronic device, storage medium and program product provided in the embodiments of the present application, by determining a fracturing well in a site to be tested and a plurality of test wells that satisfy a preset position relationship with the fracturing well, wherein the site to be tested is a site that satisfies the test conditions after lithological analysis of a plurality of test sites at different geographical locations; determining the geostress state of the target test well, wherein the position of the target test well and the position of the fracturing well satisfy a first distance requirement; performing a fracturing test on the fracturing well according to the geostress state and preset hydraulic fracturing process parameters, and obtaining data collected by a detection device, wherein the detection device is a device pre-deployed in the site to be tested for collecting data during the fracturing process, and the detection device includes a fracturing device, a microseismic station, an electromagnetic device, an acoustic optical fiber, a strain optical fiber, and a seepage device; determining fracture network characterization information based on a rock mass section image at a preset position of the site to be tested, and the fracture network characterization information is used to indicate the fracture morphology and proppant distribution formed by fracturing situation; according to the collected data, the fracturing test process is inverted to obtain the dynamic process information of fracturing, which includes the process of crack formation, the flow process of fracturing fluid, the deformation process of formation, and the migration process of proppant; according to the comparison results between the dynamic process information of fracturing and the characterization information of fracture network, a hydraulic fracturing process optimization scheme is generated, which is used to optimize the preset hydraulic fracturing process parameters and hydraulic fracturing steps, and utilizes systematic test site selection, accurate ground stress state assessment, and data collection of various detection equipment, combined with the fracture network characterization of rock section images, to comprehensively improve the accuracy and practicality of the hydraulic fracturing test results. At the same time, the inversion analysis of the collected data is used to obtain detailed dynamic process information of fracturing, and it is compared with the fracture network characterization information to generate an optimized hydraulic fracturing process scheme, which can solve the problem of insufficient accuracy of the overall fracture characterization in traditional methods and improve the reservoir operation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0053] Figure 1 A schematic diagram of the hydraulic fracturing pilot test method provided for this application;

[0054] Figure 2 A schematic diagram of data collection during the hydraulic fracturing pilot test provided for this application;

[0055] Figure 3a A schematic diagram of the well location during the drilling preparation phase provided for this application;

[0056] Figure 3b A schematic diagram of a fracturing well structure in the drilling preparation stage provided for this application;

[0057] Figure 4 A schematic diagram of the overall deployment of the detection equipment provided for this application;

[0058] Figure 5a Schematic diagram of the geostress testing phase provided for this application;

[0059] Figure 5b A schematic diagram of pressure and flow data of the test well 10 at a depth of 7.8 m during the geostress test phase provided in this application;

[0060] Figure 5c A schematic diagram of the well wall crack morphology of the test well 10 at a depth of 7.8 m during the geostress test phase provided in this application;

[0061] Figure 6 A schematic diagram of a fracturing curve for the hydraulic fracturing stage provided for this application;

[0062] Figure 7 Schematic diagram of the rock mass at the sectioning stage provided for this application;

[0063] Figure 8 A schematic diagram of the structure of the hydraulic fracturing pilot test device provided in this application;

[0064] Fig. 9 A schematic diagram of the structure of the electronic device provided in this application.

[0065] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0066] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0067] In the prior art, the research on the formation law of hydraulic fracturing network is mainly concentrated in two aspects: laboratory and mine. In laboratory research, small-scale testing technology is usually used to simulate the hydraulic fracturing process. However, there is a large scale gap between these laboratory tests and the cracks in actual construction, and it is impossible to simulate the real whole process of hydraulic fracturing crack formation, sand addition, closure, etc. In the mine, the method of coring around the well after fracturing can describe the expansion direction and number of cracks, and indicate the opening of the perforation cluster cracks. However, this method can only observe the crack characteristics in the coring well, and cannot know the overall picture of the fracture network. In addition, the accuracy of many fracture information inverted by the monitoring method is difficult to verify. At the same time, the experimental cost is high, the cycle is long, and the practicality is poor. The scale of direct application from indoor experiments to reservoirs is too large, and there is a lack of intermediate scale verification. It is difficult to reflect the real working conditions of fracturing and cannot effectively guide mine practice.

[0068] In order to solve the above problems, we can select a suitable test site by comprehensively utilizing lithology analysis, and reasonably arrange fracturing wells and test wells in the site to ensure the validity of the test data; by evaluating the ground stress state of the target test well, combined with multi-dimensional data acquisition of various detection equipment (such as microseismic stations, electromagnetic equipment, acoustic optical fiber, etc.), the physical and chemical changes in the fracturing process can be fully captured; based on the rock section image, the characterization information of the fracture network is constructed to provide a detailed basis for optimizing the fracturing process; through the inversion analysis of the collected data, the dynamic process information of the fracturing is obtained, including processes such as fracture formation, fracturing fluid flow, formation deformation and proppant migration; finally, the dynamic process information is compared with the fracture network characterization information to generate an optimized hydraulic fracturing process plan, thereby significantly improving the accuracy and practicality of the hydraulic fracturing process and achieving more efficient reservoir operations.

[0069] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0070] The execution subject of the hydraulic fracturing pilot test method provided in the embodiment of the present application may be a server. The server may be a mobile phone, a computer, a tablet or other device. The embodiment of the present application does not impose any special restrictions on the implementation method of the execution subject, as long as the execution subject can determine the fracturing well in the test site and multiple test wells that meet the preset position relationship with the fracturing well, and the test site is a site that meets the test conditions after lithological analysis of multiple test sites in different geographical locations; determine the ground stress state of the target test well, wherein the position of the target test well and the position of the fracturing well meet the first distance requirement; perform a fracturing test on the fracturing well according to the ground stress state and the preset hydraulic fracturing process parameters to obtain the collected data of the detection equipment, wherein the detection equipment is a device pre-deployed in the test site for collecting data during the fracturing process, and the detection equipment includes a fracturing device, Microseismic stations, electromagnetic equipment, acoustic optical fiber, strain optical fiber, seepage equipment; based on the rock section image at the preset position of the test site, determine the fracture network characterization information, the fracture network characterization information is used to indicate the fracture morphology and proppant distribution of the fracture formed by fracturing; according to the collected data, the fracturing test process is inverted to obtain the fracturing dynamic process information, the fracturing dynamic process information includes the fracture formation process, the fracturing fluid flow process, the formation deformation process, and the proppant migration process; according to the comparison results between the fracturing dynamic process information and the fracture network characterization information, generate a hydraulic fracturing process optimization plan, the hydraulic fracturing process optimization plan is used to optimize the preset hydraulic fracturing process parameters and hydraulic fracturing steps.

[0071] Figure 1 The following is a schematic diagram of the hydraulic fracturing pilot test method provided in this application. Figure 1 As shown, the method may include:

[0072] S101, determining a fracturing well in a site to be tested and a plurality of test wells that satisfy a preset position relationship with the fracturing well, wherein the site to be tested is a site that satisfies test conditions after lithology analysis is performed on a plurality of test sites at different geographical locations.

[0073] Among them, a fracturing well can be a well into which high-pressure fluid is directly injected to create cracks during a hydraulic fracturing operation, the purpose of which is to fracture the surrounding rocks through high-pressure liquid to provide a flow channel for oil and gas.

[0074] Test wells can be wells used to monitor and obtain data related to the fracturing process. These wells have a specific spatial layout relationship with the fracturing wells so as to collect information from different angles and locations.

[0075] The preset position relationship may refer to a preset geometric relationship between the fracturing well and the test well, such as the distance and direction. For example, the test wells may be required to be arranged in a specific circular or square layout around the fracturing well, and the distance may be within a certain range, so as to comprehensively and effectively monitor the fracturing affected area.

[0076] Lithology analysis can be a study and evaluation of the rock structure and composition of test sites in different geographical locations. Only when the lithology meets certain requirements, such as a flat and unweathered rock surface, a certain degree of brittleness, and a certain composition ratio, can it be used as a site that meets the test conditions.

[0077] Optionally, the rock outcrop of the selected test site needs to ensure that there is no obvious weathering. If the weathering is serious, it is necessary to pre-treat and peel off the weathering layer until it is similar to the reservoir rock, and clean it to make the platform surface flat. For example, through geological exploration techniques, such as seismic exploration, core sampling, etc., lithology analysis is performed on multiple potential test sites. If it is found that the rock mass in a certain area is uniform and has no cracks, and the main components are plagioclase, with a content of 75.2%, quartz content of 17%, and clay of about 4.7%, it is judged that the test conditions are met; then, in the determined test site where the platform surface is flat, with the fracturing well as the center, the locations of multiple test wells are determined according to the preset distance (such as 9 meters, 12 meters, 19 meters, etc.) and direction (such as due east, due south, due west, due north, and 45 degrees to these directions, etc.).

[0078] S102: Determine the ground stress state of the target test well, wherein the location of the target test well and the location of the fracturing well meet a first distance requirement.

[0079] Among them, the geostress state can refer to the stress conditions that rocks are subjected to in the earth's crust, including vertical stress (caused by the weight of overlying rock layers) and horizontal stress (caused by crustal tectonic movements, etc.). The geostress state has a key influence on the initiation direction and expansion shape of hydraulic fracturing cracks.

[0080] The first distance requirement may refer to a specific distance standard between the target test well and the fracturing well. This distance is designed to enable the target test well to better reflect the geostress characteristics near the fracturing well, while avoiding being too close to the fracturing well and being directly affected by fracturing, resulting in inaccurate measurements. For example, it may be set to 12 meters.

[0081] In one example, hydraulic fracturing is used to test geostress, and the wellbore used is one of the test wells. The size and direction of the geostress are determined by the data collected by the detection equipment; or microseismic monitoring technology is used to analyze the propagation characteristics of seismic waves generated by a small-scale artificial seismic source near the target test well to infer the geostress state.

[0082] S103. Perform a fracturing test on the fracturing well according to the ground stress state and preset hydraulic fracturing process parameters to obtain data collected by the detection equipment, wherein the detection equipment is a device pre-deployed in the test site for collecting data during the fracturing process, and the detection equipment includes fracturing equipment, microseismic stations, electromagnetic equipment, acoustic optical fibers, strain optical fibers, and seepage equipment.

[0083] In this step, the preset hydraulic fracturing process parameters may include the type of fracturing fluid (such as water-based fracturing fluid, oil-based fracturing fluid, etc.), viscosity, injection pressure, injection rate, sand addition amount, sand ratio and other parameters set before the fracturing operation. The selection of these parameters will directly affect the fracturing effect.

[0084] Among them, different combinations of detection equipment can be selected according to test requirements and geological conditions. For example, under complex geological conditions, more microseismic stations may be required to improve data accuracy.

[0085] Fracturing equipment can be equipment used to inject high-pressure liquid and proppant into fracturing wells, such as a sand mixer. Microseismic stations can be instruments deployed on the surface and side facing surfaces of the site to be tested, used to monitor microseismic events caused by rock fractures during hydraulic fracturing, and infer the expansion of cracks by analyzing the characteristics of microseismic signals (such as source location, magnitude, frequency, etc.). Electromagnetic equipment can indirectly judge the distribution of fracturing fluid and changes in formation structure by measuring changes in electromagnetic properties at different depths underground, reflecting changes in formation resistivity, because the injection of fracturing fluid will change the conductivity of the formation. Acoustic fiber, such as DAS (Distributed Acoustic Sensing) fiber, can use optical fiber as a sensing element, and by monitoring changes in the propagation characteristics of sound waves in the optical fiber, it can sense the acoustic response of rocks during fracturing, such as the reflection, refraction and attenuation of sound waves when cracks are generated, and then understand the development of cracks. Strain optical fiber, such as DSS (Distributed Strain Sensing) optical fiber, is also based on optical fiber sensing technology, which measures the strain changes of rocks during fracturing and determines the deformation of the formation, which helps to analyze the expansion direction and scale of the cracks. Seepage equipment can be equipment used to monitor the seepage of fluids in the formation after fracturing, such as pressure sensors, flow sensors, etc., which can understand the improvement effect of fracturing on the permeability of the formation and the influence of proppants on the seepage channel.

[0086] S104, determining fracture network characterization information based on a rock mass section image at a preset position of the site to be tested, where the fracture network characterization information is used to indicate fracture morphology and proppant distribution conditions formed by hydraulic fracturing.

[0087] The rock section image may be an image obtained by sectioning the rock at a preset position (such as performing virtual section imaging of underground rock using geophysical imaging technology), and is used to visually observe the morphology of the fracture network and the distribution of proppants in the fractures.

[0088] Fracture network characterization information can include morphological characteristics such as fracture length, width, height, density, connectivity, and information such as the concentration and distribution uniformity of proppants in the fractures. This information is used to evaluate the fracturing effect and optimize the process.

[0089] S105. Invert the fracturing test process according to the collected data to obtain fracturing dynamic process information, which includes crack formation process, fracturing fluid flow process, formation deformation process, and proppant migration process.

[0090] Among them, inversion can refer to the use of mathematical models and calculation methods to reversely infer various dynamic processes in the fracturing process based on the data collected by the detection equipment, such as the time, position, and direction of crack formation, the flow rate and pressure distribution of the fracturing fluid in the cracks, the degree and range of deformation of the formation during the fracturing process, the migration trajectory and deposition of the proppant in the cracks, etc.

[0091] Furthermore, the steps of inverting the fracturing test process may be: inverting based on the microseismic event data and acoustic wave signals in the acquired data to determine the crack formation process; inverting based on the pressure, flow and formation electromagnetic parameter data in the acquired data to determine the fracturing fluid flow process; inverting based on the acoustic wave signals and strain data in the acquired data to determine the formation deformation process; inverting based on the mixed fluid injection parameters, and the flow, microseismic event data and acoustic wave signals in the acquired data to determine the proppant migration process; wherein the fracturing dynamic process information includes the crack formation process, the fracturing fluid flow process, the formation deformation process, and the proppant migration process.

[0092] The fracturing dynamic process information covers detailed information related to fracture formation, fracturing fluid flow, formation deformation, and proppant migration from the beginning to the end of fracturing.

[0093] Optionally, for microseismic data, a source location algorithm is used to calculate the location of the microseismic source based on the time difference of microseismic signals received by different microseismic stations, combined with a known formation wave velocity model, to determine the expansion path of the fracture. Using the finite element numerical simulation method, the formation resistivity changes measured by electromagnetic equipment, the acoustic wave data monitored by acoustic fiber, and the strain data measured by strain fiber are input into the model as boundary conditions or constraints to simulate the flow of fracturing fluid in the fracture, the deformation of the formation, and the migration process of the proppant, and obtain the dynamic process information of the fracturing.

[0094] In one example, the crack formation process may include: processing microseismic event data, determining the three-dimensional position of the earthquake source based on the positioning algorithm, the time difference of the station receiving signal and the formation wave velocity model, and its spatiotemporal distribution indicating the position and sequence of crack formation; analyzing the parameters of the acoustic wave reflection wave to determine the boundary morphology of the crack, and combining the two to obtain information such as the initiation, expansion, and extension of the crack.

[0095] The fracturing fluid flow process may include: using pressure and flow as boundary conditions, using fluid mechanics principles and numerical simulation, and combining Darcy's law with formation parameters to simulate its flow in fractures and pores; using formation electromagnetic parameters for correction, comparing electromagnetic and fluid models, and confirming flow paths, velocities, and retention conditions.

[0096] The formation deformation process can include: analyzing the changes in sound wave propagation parameters, combining strain data, inferring the rock stress state based on models such as wave equations, and using numerical methods to build a three-dimensional deformation model to show the deformation range, direction and degree differences.

[0097] The proppant migration process may include: based on the mixed liquid injection parameters and flow rate, using multiphase flow theory to simulate proppant migration and deposition, using microseismic and acoustic signal monitoring and correction, and building a full process model to determine its concentration and velocity distribution.

[0098] By using different types of collected data to invert various aspects of the fracturing dynamic process, all-round and refined monitoring and analysis of the hydraulic fracturing test process is achieved. At the same time, this multi-data fusion inversion method can overcome the limitations of a single data source and more accurately restore the complex physical phenomena and processes in the hydraulic fracturing process, providing rich and reliable information for a deep understanding of the hydraulic fracturing mechanism, and thus providing a high-precision basis for optimizing the hydraulic fracturing process.

[0099] S106. Generate a hydraulic fracturing process optimization plan based on the comparison result between the fracturing dynamic process information and the fracture network characterization information. The hydraulic fracturing process optimization plan is used to optimize the preset hydraulic fracturing process parameters and hydraulic fracturing steps.

[0100] In this step, the fracturing dynamic process information obtained by inversion is compared and analyzed with the fracture network characterization information determined by the rock section image to obtain comparison results, such as the differences and consistencies in fracture morphology, proppant distribution, etc.

[0101] The hydraulic fracturing process optimization plan can be a plan for adjusting and optimizing the preset hydraulic fracturing process parameters (such as fracturing fluid type, viscosity, injection pressure, sand addition amount, etc.) and hydraulic fracturing steps (such as injection sequence, stage spacing of multi-stage fracturing, etc.) based on the comparison results, so as to improve the effect and efficiency of hydraulic fracturing.

[0102] In one example, if the comparison results show that the fracture height obtained by inversion is lower than the actual fracture height shown in the rock section image, it may be considered to increase the viscosity of the fracturing fluid or the injection pressure to improve the extension capacity of the fracture. If it is found that the proppant is unevenly distributed in the fracture, the sand addition method may be adjusted (such as changing the gradient of the sand ratio, using a combination of proppants with different particle sizes, etc.) or the sand carrying performance of the fracturing fluid may be optimized.

[0103] The hydraulic fracturing pilot test method provided in the embodiment of the present application comprehensively monitors the fracturing process by determining a suitable test site, test well layout, and detailed ground stress measurements, combined with a variety of advanced detection equipment; the fracturing dynamic process information is obtained from the collected data using inversion technology, and compared with the fracture network characterization information determined by the rock section image, and finally an optimization plan is generated. This method effectively bridges the scale gap between traditional laboratory research and actual mine application, solves the problem that the laboratory cannot simulate the real whole process and the mine research information is inaccurate and incomplete, can more accurately reflect the real working conditions of hydraulic fracturing, provide a scientific basis for the optimization of hydraulic fracturing process parameters and steps, improve the effectiveness and economy of hydraulic fracturing in unconventional oil and gas production, and reduce unnecessary cost investment and resource waste.

[0104] Based on the above embodiments, the method described in S101 for determining the fracturing wells in the site to be tested and multiple test wells that satisfy a preset position relationship with the fracturing wells may include: obtaining lithology information of the site to be tested; and performing core drilling in the site to be tested according to the lithology information and preset drilling design parameters to obtain the fracturing wells in the site to be tested and multiple test wells that satisfy a preset position relationship with the fracturing wells.

[0105] Among them, lithology information can refer to the rock type, physical properties of the rock, and mineral composition of the rock in the test site. For example, the lithology characteristics of shale are usually low porosity and low permeability, but rich in organic matter. During hydraulic fracturing, the formation and expansion of its cracks are quite different from those of other rock types such as sandstone.

[0106] Optionally, through regional geological surveys, the distribution of strata in the area can be studied to understand the possible rock types in different strata; the properties of rocks and stratigraphic structure can be inferred by analyzing the propagation speed, reflection and refraction characteristics of seismic waves in underground rocks; a small amount of drilling and coring work can be carried out, and the cores taken out can be subjected to laboratory analysis to determine their porosity, permeability, mineral composition and other parameters, so as to obtain more accurate lithology information.

[0107] The preset drilling design parameters can be a series of parameters pre-set before the drilling operation, including the depth of the well, the diameter of the well, the azimuth of the well, the spacing between wells, etc. The setting of these parameters needs to comprehensively consider the lithology information, geological structure, test purpose, and on-site construction conditions. For example, if the rock is hard, it is necessary to adjust the drilling bit type and the drilling speed, pressure and other parameters to ensure smooth drilling; if it is to fully monitor the situation in different directions around the fracturing well, the azimuth of the well will be distributed at a certain angle interval (such as 45 degrees).

[0108] In one example, a coring drilling method is used to obtain formation cores while drilling for subsequent experimental testing and analysis. The drilling includes fracturing wells and test wells. During the drilling process, coring is performed throughout the entire process to determine the wellbore and well number of each well. The core samples obtained are classified according to the well number and placed in the core box one by one according to the depth.

[0109] Optionally, the fracturing well drilling process can be as follows: the drill bit is drilled to the target depth, the drill bit diameter is selected as needed, and the wellbore diameter is generally selected to facilitate the subsequent construction tools and cementing casing to be lowered, and the outer diameter of the cementing casing and the inner diameter of the wellbore should be no less than 20 mm to ensure that the cementing fluid can be easily squeezed into the annulus.

[0110] The test well drilling process can be as follows: the drill bit is drilled to the target depth, the drilling depth is 1.5 times the wellbore depth of the fracturing well, the drill bit diameter is selected as needed to ensure that the wellbore diameter after drilling is convenient for the subsequent testing equipment to enter the well for construction. The test well location should be at a horizontal distance from the fracturing well, which should be greater than 1.5 times the expected extension distance of the hydraulic fracturing crack.

[0111] By obtaining the lithology information of the site to be tested and optimizing the preset drilling design parameters to perform drilling and coring operations, it is possible to ensure that the location and wellbore quality of the fracturing well and the test well are more reasonable. On the one hand, the adjustment of drilling parameters based on lithology information can improve drilling efficiency and reduce the probability of drilling accidents (such as wellbore collapse, drill stuck, etc.); on the other hand, the reasonable determination of the positional relationship between the fracturing well and the test well will help to monitor the hydraulic fracturing process more comprehensively and accurately. Test wells at different locations can capture information such as crack expansion, fluid seepage, and formation deformation caused by fracturing from multiple angles, better predict and control the formation and expansion of cracks, and improve the accuracy and effectiveness of fracturing tests.

[0112] On the basis of the above embodiments, the method may further include: pre-processing the cementing casing to determine the target cementing casing and the installation status of the target cementing casing; if the installation status indicates that the target cementing casing meets the installation conditions, deploying the target cementing casing to the fracturing well; according to the preset in-pipe introduction requirements, introducing the cementing material from the cementing casing to the bottom of the fracturing well, and according to the preset out-pipe introduction requirements, introducing the cementing material between the cementing casing and the well wall of the fracturing well; when the cementing material solidifies, drilling the fracturing well from the cementing casing until the depth of the fracturing well meets the preset depth, thereby obtaining the cemented fracturing well.

[0113] The target cementing casing may be a casing selected from a large number of cementing casings to meet specific requirements and prepared for cementing operations in the current fracturing well. For example, the target cementing casing is a casing with a rough surface without coating after grinding.

[0114] The state to be installed may refer to the comprehensive evaluation state of various preparations and characteristics of the cementing casing before installation, including the installation of a centralizer, a rubber water-expandable ring, and a flow-blocking ring on the outer surface of the casing.

[0115] For example, the outer diameter of the centralizer and the inner diameter of the wellbore of the fracturing well are guaranteed to have a clearance greater than 5mm, and the rubber water-expandable ring and the inner diameter of the wellbore of the fracturing well are guaranteed to have a clearance greater than 15mm. The centralizer and the rubber water-expandable ring are fixed to the outside of the casing to ensure that the casing does not move during the lowering process; the flow-blocking ring and the inner diameter of the wellbore of the fracturing well are guaranteed to have a clearance greater than 15mm, and are welded and fixed to the outside of the casing. Furthermore, the centralizer is installed at 1 / 4, 1 / 2, and 3 / 4 of the top of the casing, the rubber water-expandable ring is installed at 2 / 5 and 3 / 5 of the top of the casing, and the flow-blocking ring is installed at 1 / 5, 3 / 5, and 4 / 5. The length of the casing should be longer than the drilling depth of 0.5m, and a thread is reserved at the top to achieve a sealed connection with the extension pipe of the fracturing pump truck.

[0116] The preset in-pipe introduction requirements may refer to the pre-set parameters and operating specifications for conveying cementing materials through the cementing casing to the bottom of the well. For example, the mixed cementing epoxy resin or cementing cement is introduced from the casing to the bottom of the well using a funnel. The amount introduced each time is less than 2L, and vibration to generate bubbles is reduced to avoid excessive single introduction causing heat and cracking, which increases the risk of cementing failure. The return height in the casing should be 0.2-0.5m.

[0117] The preset external introduction requirements can refer to the relevant requirements for the injection of cementing materials into the annular space between the cementing casing and the wall of the fracturing well. For example, after waiting for the return height inside the casing to reach the requirement and solidify, cementing epoxy resin glue or cementing cement is introduced from the cementing casing and the annular hole of the fracturing wellbore. The amount introduced each time is less than 2L, and vibration is reduced to generate bubbles to avoid excessive single introduction causing heat and cracking, which increases the risk of cementing failure. The process is repeated many times until it returns to the surface. During the process, care should be taken to operate carefully to avoid damaging the accessories outside the cementing casing.

[0118] The preset depth may refer to the depth difference between the fracturing well and the fracturing well depth in the preset drilling design parameters after the cementing material solidifies. Secondary drilling is required to connect the cementing casing to the formation where the fracturing well depth is located. Optionally, based on the perforating operation, the perforating gun is lowered from the cementing casing to the fracturing well depth, and perforations are performed according to the design requirements; based on the secondary open hole operation, the secondary drilling is performed using a drilling method smaller than the inner diameter of the cementing casing. The diameter of the secondary wellbore should be at least 40mm smaller than the inner diameter of the cementing casing, and the secondary drilling can be performed to the preset depth.

[0119] Optionally, the step of deploying the target cementing casing to the fracturing well may include: checking whether there are any problems with the deployment. For example, using a crane or other equipment that can lift the weight of the cementing casing, the cementing casing is hoisted and placed in the fracturing well, and the cementing casing naturally falls to the bottom of the well and is in a centered position, ensuring that during the placement process, accessories such as the centralizer, rubber water-expandable ring, and flow-blocking ring installed on the outer surface of the casing are not damaged or fall off. If there are any of the above problems, they need to be repaired and then lowered again until the casing falls to the bottom of the well and is centered, and the accessories are intact.

[0120] The cementing quality is effectively improved through careful pretreatment, accurate screening and standardized installation of cementing casing and reasonable cementing material introduction operation; a stable and well-sealed cementing layer is formed between the cementing casing and the well wall, which can prevent the cross-flow of formation fluids and provide a safe and reliable wellbore environment for subsequent hydraulic fracturing operations. At the same time, the structure of the fracturing well after cementing is stable and can withstand the pressure fluctuations during high-pressure fracturing, ensuring the smooth progress of hydraulic fracturing operations.

[0121] On the basis of the above-mentioned embodiment, before determining the ground stress state of the target test well as described in S102, the method may also include: obtaining core samples from the fracturing well and each test well; performing a bedding structure analysis on all the core samples to determine a first test well that meets the bedding distribution conditions; deploying the electrodes of the electromagnetic device inside the first test well, and deploying the electrodes of the electromagnetic device for testing the formation resistance on the ground at the location of the second test well, wherein the location of the second test well and the location of the fracturing well meet a second distance requirement; deploying the fracturing equipment on the ground at the location of the fracturing well, and connecting the connecting pipe of the fracturing equipment to the cementing casing of the fracturing well. connection; deploying microseismic stations on the ground and side facing surfaces of the site to be tested; deploying the acoustic optical fiber from the bottom of the third test well to the ground, and deploying it in the site to be tested based on a preset ground trajectory, and the position of the third test well and the position of the fracturing well meet the third distance requirement; deploying the strain optical fiber from the bottom of the first target test well to the ground, and entering the second target test well through the ground between the first target test well and the second target test well, and when the strain optical fiber is deployed to the bottom of the second target test well, it returns to the ground through the second target test well; deploying the seepage equipment at the wellhead of the second test well, and the seepage equipment includes a pressure meter and a flow meter.

[0122] Among them, core samples are cylindrical rock samples obtained through drilling and coring operations in fracturing wells and various test wells. These samples can intuitively reflect the various characteristics of underground rocks, such as the mineral composition, pore structure, and bedding characteristics of the rocks.

[0123] Bedding structure is the layered feature formed in the process of rock deposition. Rocks with different bedding may have differences in mechanical properties, permeability, etc., which will affect the effect of hydraulic fracturing. By analyzing the core samples, the location of obvious bedding in each core sample can be determined, and the corresponding detection equipment can be deployed in the first test well with obvious bedding thickness, which can more accurately detect the data in the fracturing process.

[0124] The second distance requirement refers to the specific spatial distance setting between the second test well and the fracturing well. The selection of this distance must take into account both the effective monitoring of the impact of fracturing on the surrounding formation resistance and the avoidance of being too close to the fracturing well and being directly disturbed by fracturing, resulting in inaccurate measurements. For example, it is set to 9m.

[0125] The side-to-air surface refers to the surface on the side of the rock mass that is directly in contact with the air without support or constraint. The deployment of this surface can increase the monitoring angle and range, better capture microseismic signals propagating from different directions underground, and thus fully understand the expansion of cracks.

[0126] The third distance requirement is similar to the distance requirement mentioned above, which is to enable the third test well to monitor fracturing related information at an appropriate location, for example, set to 19m. The preset ground track refers to laying optical fiber on the ground according to a pre-designed route to better cooperate with other monitoring equipment or expand the monitoring range.

[0127] The first target test well and the second target test well are specific test wells selected for strain monitoring. This cross-well deployment method can obtain strain correlation information of formations at different locations during the fracturing process, which is helpful for analyzing the expansion direction and scale of cracks.

[0128] Optionally, the deployment of electromagnetic equipment can also be as follows: on the platform of the test site, with the fracturing well as the center, along the outward radiation radius, electromagnetic testing equipment is arranged to test the horizontal formation resistivity data, and electromagnetic testing equipment is arranged in the test well to test the vertical formation resistivity data.

[0129] Fracturing equipment can provide the pressure and flow required for hydraulic fracturing and record the pressure and flow data. Fracturing equipment generally includes four parts: fracturing truck, fracturing sand mixer truck, instrument truck and connecting pipe, which can meet the pumping requirements of fracturing fluid and proppant required for testing. Connect the instrument truck, fracturing sand mixer truck and fracturing truck in sequence and connect them to the top of the cementing casing of the fracturing well through the connecting pipe. All connections are sealed without leakage points.

[0130] Microseismic stations can be arranged on the platform surface of the test site, with the fracturing well as the center and radiating outward one by one. The arrangement density increases from dense to sparse. For the extension direction of the fractures of concern, the arrangement density can be appropriately increased to ensure that the arrangement range covers the entire test platform.

[0131] The deployment of acoustic fiber can also be as follows: the tail end of the fiber is stretched to the bottom of the test well using a plumb bob to center the fiber, dry sand is poured into the well to the surface, and then the fiber is wrapped around the edge of the test platform, which can be wrapped multiple times to achieve overall coverage of the test platform, and finally connected to the DAS data acquisition equipment.

[0132] The deployment of strain fiber can also be as follows: the tail end of the fiber is stretched to the bottom of the test well using a plumb bob to center the fiber, dry sand is poured into the well to the surface, and then the fiber is wrapped around the edge of the test platform, which can be wrapped multiple times to achieve overall coverage of the test platform, and finally connected to the DSS data acquisition equipment.

[0133] By rationally deploying a variety of detection equipment and comprehensively monitoring the hydraulic fracturing process from different angles and positions, rich and accurate formation information can be obtained, which helps to gain a deeper understanding of complex physical processes such as crack formation, expansion, formation deformation, and fluid seepage during the hydraulic fracturing process. This provides accurate and comprehensive data support for accurately inverting the fracturing dynamic process, evaluating the fracturing effect, and formulating scientific and reasonable hydraulic fracturing process optimization plans.

[0134] On the basis of the above-mentioned embodiment, the method described in S103 for performing a fracturing test on a fracturing well according to the ground stress state and preset hydraulic fracturing process parameters to obtain collected data of the detection equipment may include: determining fracturing fluid injection parameters and mixed liquid injection parameters according to the ground stress state and preset hydraulic fracturing process parameters, wherein the mixed liquid includes fracturing fluid and proppant, the fracturing fluid is a fracturing fluid with fluorescent powder added, and the proppant is a proppant with preset dye added; performing a fracturing test on the fracturing well according to the fracturing fluid injection parameters and the mixed liquid injection parameters to obtain collected data of the detection equipment, wherein the collected data includes pressure, flow, microseismic event data, formation electromagnetic parameter data, acoustic wave signals, and strain data during the fracturing process.

[0135] Among them, the fracturing fluid injection parameters may refer to various control parameters involved in the fracturing fluid injection stage during the hydraulic fracturing process, which may include the injection rate of the fracturing fluid (e.g., how many cubic meters of fracturing fluid are injected per minute), the injection pressure (the pressure value maintained at different stages), the injection time (the time from the start of fracturing fluid injection to the stop or conversion of the injection of the mixed fluid), etc. These parameters directly affect the penetration and diffusion of the fracturing fluid in the underground rock and the initial cracking of the cracks.

[0136] Mixed liquid injection parameters may refer to the relevant control parameters when the mixed liquid containing fracturing fluid and proppant is injected. In addition to being similar to the fracturing fluid injection parameters, they also involve the concentration of the proppant (such as the mass or volume ratio of the proppant per cubic meter of mixed liquid), the particle size distribution of the proppant, etc. The proppant concentration affects the supporting effect of the fracture. The appropriate concentration can keep the fracture from closing after fracturing, while the particle size distribution is related to the characteristics of the fracture width, etc. The combination of proppants with different particle sizes can better meet the needs of different parts of the fracture.

[0137] Fluorescent powder is added to the fracturing fluid for marking to distinguish reservoir water from the fracturing fluid, and to avoid confusion between natural fractures and hydraulic fractures during post-fracture sectioning and identification. The fracturing fluid can be selected for testing in the fracturing process. For example, through a fluorescent microscope or specific fluorescent detection equipment, the area where the fracturing fluid has been can be clearly seen.

[0138] Preset dyes are added to the proppant to distinguish it from formation rock cuttings and sand particles. The proppant can be selected to be tested in the fracturing process. For example, red paint is used for dyeing and marking. When observing the core or formation, the red proppant particles can be used to intuitively understand the deposition of the proppant in the fracture network.

[0139] It should be noted that the particle sizes of phosphor and proppant can be set according to actual engineering requirements. For example, based on the laser diffraction test method, the particle size range of phosphor is 2.98-262.38μm, and the particle size range of proppant is 34.26-2636.47μm; according to actual engineering requirements, the particle size of phosphor is set to 13.25μm, and the particle size of proppant is set to 451.56μm.

[0140] In one example, the injection flow rate is set for the fracturing truck according to the injection parameters of the fracturing fluid and the mixed liquid injection parameters, and the matching sand mixing truck is used to mix the fracturing fluid and the proppant. The fracturing fluid flows through the sand mixing truck, and is mixed with the proppant before being discharged by the fracturing truck. Among them, the fracturing test is divided into two stages: ① Inject pure fracturing fluid at a certain flow rate, and record the injection pressure and the volume of injected fracturing fluid during the process; ② Inject the mixed liquid formed by mixing fracturing fluid and proppant at a certain flow rate, and record the injection pressure, the volume of injected fracturing fluid, and the volume of proppant used during the test. At the same time, before the fracturing test begins, turn on the microseismic station, electromagnetic equipment, DAS fiber optic equipment, and DSS fiber optic equipment to record and store data throughout the process.

[0141] In this embodiment, it can be understood that microseismic event data is obtained from the microseismic station, which can be relevant data when rock fractures and produces tiny earthquakes during hydraulic fracturing, reflecting the spatiotemporal distribution characteristics of rock fractures; formation electromagnetic parameter data is obtained from the electromagnetic equipment, such as the resistivity change of the formation during hydraulic fracturing; sound wave signals are obtained from the acoustic optical fiber, such as the propagation signal of sound waves in the rock medium during the formation of cracks; strain data is obtained from the strain optical fiber, such as the strain change data of the rock during the fracturing process, reflecting the length change of the rock in different directions, directly reflecting the deformation of the formation; pressure and flow are obtained from the seepage equipment, such as data reflecting the pressure change at different positions during the fracturing process, the injection flow during the fracturing fluid injection process, and the possible output flow data monitored in the test well.

[0142] By adding fluorescent powder to the fracturing fluid and preset dyes to the proppant, the distribution of the fracturing fluid and proppant in the fracture network can be quickly and accurately identified, and the fracturing effect and the deposition state of the proppant can be intuitively understood, providing strong support for the accurate acquisition of fracture network characterization information. At the same time, according to the set injection parameters, fracturing tests are carried out and multi-faceted test data are collected, which can more comprehensively and accurately invert the dynamic process information of fracturing, thereby improving the scientificity and reliability of the hydraulic fracturing process optimization plan, and improving the efficiency and success rate of hydraulic fracturing operations in unconventional oil and gas production.

[0143] On the basis of the above-mentioned embodiments, the method described in S104 for determining the fracture network characterization information based on the rock section image at the preset position of the test site may include: sectioning the rock at the preset position of the test site to obtain a plurality of sectioned rock masses at different sectioning depths; for each sectioned rock mass, determining the fracture area image in the sectioned rock mass based on the light corresponding to the fluorescent powder; determining the proppant area image in the sectioned rock mass based on the color of the preset dye; and based on the three-dimensional reconstruction method, superimposing the rock section images corresponding to each sectioned rock mass according to the sectioning depth to construct a three-dimensional model; wherein the rock section image includes a fracture area image and a proppant area image, and the fracture network characterization information is determined by the three-dimensional fracture morphology and proppant distribution in the three-dimensional model.

[0144] The cutting method may be to peel the rock mass by cutting, cut it vertically layer by layer, and then take pictures to collect the fracture area and proppant area in each section where the cut rock mass is located.

[0145] Furthermore, due to the properties of the fluorescent powder in the fracturing fluid, a light source with a specific wavelength (such as an ultraviolet light) that can excite fluorescence is used to monitor the cut rock mass, and the angle and intensity of the light source are adjusted to optimize the fluorescence effect. A high-resolution camera (preferably with a macro function) is used to capture the cross-section to obtain an image of the fracture area. The proppant contains a preset dye, and the proppant area image corresponding to the color of the preset dye can be directly observed and determined by capturing the image.

[0146] Since the distribution of fractures and proppants in the rock mass is three-dimensional, a series of images reflecting the internal conditions of the rock mass at different levels can be obtained by performing sectioning operations at multiple depths, so as to facilitate the subsequent establishment of a three-dimensional model to describe the distribution of fractures and proppants in the rock mass.

[0147] In this step, the 3D reconstruction method is a technology that integrates multiple 2D image information and reconstructs it into a 3D model. The images of the fracture area and proppant area in the cut rock mass at different cutting depths are converted into a 3D model in 3D space through a specific algorithm and mathematical model to intuitively display the 3D distribution of the fracture network and proppant.

[0148] Through multi-step processing of the sectioned rock mass, from obtaining images of the fracture area and proppant area of ​​the rock mass at different depths, to using the three-dimensional reconstruction method to construct a three-dimensional model to display the fracture network and proppant distribution, the two-dimensional sectioned rock mass information can be converted into an intuitive three-dimensional model to present the three-dimensional spatial distribution characteristics of the fracture network and proppant inside the rock mass, which can more realistically reflect the fracture morphology and proppant distribution characteristics in hydraulic fracturing.

[0149] Figure 2 A schematic diagram of data collection during the hydraulic fracturing pilot test provided for this application, such as Figure 2 As shown, in this embodiment Figure 1 Based on the embodiment, taking the hydraulic test process of a specific time period in site A as an example, the hydraulic fracturing pilot test method is described in detail. The data collection of this method includes the drilling preparation stage, the ground stress test stage, the hydraulic fracturing stage, the seepage test stage, and the section reconstruction stage.

[0150] 1. Drilling preparation stage:

[0151] It includes drilling construction, core physical and bedding analysis, and indoor mechanical experiments. The collected data may include ① core ② stratigraphic bedding distribution characteristics ③ rock physical properties / mechanical data.

[0152] (1) Site A was selected from multiple experimental groups of stratigraphic layers in multiple regions. Further, based on the XRD (X-ray Diffraction) test method, by analyzing the stratigraphic information of different geological periods (including the name, symbol and corresponding code of the stratigraphic layer), and according to the test conditions such as the structure and composition of the rock, the stratigraphic layer was selected as the homogeneous sandstone of the Jiaguan Formation of the Upper Cretaceous System. The surface of the test site was flat, the rock mass was uniform and had no cracks, and the composition was mainly plagioclase with a content of 75.2%, quartz content of 17%, and clay of about 4.7%. Among them, the test size of Site A was 30m in the NS (North-South) and WE (West-East) directions and 10m in depth.

[0153] (2) Drilling is done by using a coring drilling method, and cementing is performed on the fracturing wells. Then the core samples corresponding to each well are numbered and saved. The test platform of the entire test site is 19° counterclockwise from the geographical orientation, that is, the N direction of the NS direction geometric boundary of the test site is 19° counterclockwise from the geographical N direction. Based on this, Figure 3a The well location diagram for the drilling preparation stage provided for this application. Figure 3a As shown, a total of 12 wells were drilled, among which LSH-0 well was a fracturing well located in the center of the experimental field, and the remaining wells were test wells; LSH-1 to No. 8 wells were arranged on a circle 9 m away from LSH-0 well in plane (the test platform ground of the test site), with a wellbore diameter of 75 mm and a depth of about 8.3 m; LSH-9 and LSH-10 wells were arranged in the S direction and W direction respectively, 12 m away from LSH-0 well in plane, with a wellbore diameter of 75 mm and a depth of about 19 m; LSH-11 well was arranged in the W direction, 19 m away from LSH-0 well in plane, with a wellbore diameter of 75 mm and a depth of 19 m.

[0154] Figure 3b The schematic diagram of the fracturing well structure in the drilling preparation stage provided in this application. Figure 3b As shown, the fracturing well has two openings: the fracturing well is drilled, the first opening has a wellbore diameter of 139mm and a depth of 5m, and the wellbore is cemented with a 4-inch oil pipe (such as a steel pipe with an inner diameter of 101.6mm and an outer diameter of 107.95mm), such as by placing epoxy resin; the second drilling is performed in the oil pipe, the borehole diameter is 75mm, the depth is 5.0-6.5m, and after drilling to 6.5m, subsequent fracturing construction is awaited, and the second opening wellbore is completed in the form of an open hole.

[0155] 2. Geostress testing phase:

[0156] The geostress test uses hydraulic fracturing to test geostress, and the wells used are test wells 9 and 10 to test the pressure required for fracturing. This stage includes geostress testing, acoustic imaging logging, and pressure / flow data. The collected data may include ① microseismic ② DAS fiber optic ③ electrical method ④ logging ⑤ pressure ⑥ flow.

[0157] It should be noted that before the test, the detection equipment needs to be deployed and the particle size parameters of the fluorescent powder and proppant in the fracturing fluid need to be determined in order to facilitate the collection and acquisition of test data.

[0158] Figure 4 The overall deployment diagram of the detection equipment provided for this application is as follows: Figure 4 As shown, the fracturing equipment includes a fracturing truck and a sand mixing truck, which provide the pressure and flow of hydraulic fracturing, and inject fracturing fluid and proppant. Microseismic stations (microseismic stations) are arranged on the platform surface and the side facing the empty surface, with a total of 66. Optionally, the microseismic stations also include charge chip seismometers, which are arranged at a radius of 1m and 2m in the horizontal direction of the LSH-0 well on the ground, and can detect tiny seismic waves related to fracturing activities. The electromagnetic equipment is the gray dotted line and electrode corresponding to the electric signal transmitting source. Furthermore, surface electrodes are arranged in the direction of LSH-1, 2, 3, 5, 6, 7, and 8 wells on the platform surface to monitor the changes in electromagnetic signals in the formation. For example, for each test well, electrode a is arranged on the platform surface close to the fracturing well, electrode b is arranged at a distance of 1 meter from electrode a, electrode c is arranged at a distance of 2 meters from electrode b, and electrode d is arranged at a distance of 4 meters from electrode c; optionally, electrodes are arranged in LSH-2 / 4 / 6 / 8 wells, and the distance between each electrode is 1.5 meters. Among them, since the fracturing equipment is deployed in the direction of LSH-4 well, it is not arranged in the direction of LSH-4 well. The acoustic fiber is the black solid fiber on the first platform and the black dotted fiber on the second and third platforms corresponding to the DAS collector. It is further transmitted from the bottom of the LSH-11 well to the surface, arranged in a circle on the surface, and then returned to the surface and connected to the collection equipment. The corresponding deployment parameters may include gauge length -4m, track spacing -1m, total length -200m, monitoring well depth -19m, and fracturing well depth -6.5m. The strain fiber is the gray solid fiber corresponding to the DSS collector. It is further transmitted from the bottom of the LSH-9 well to the surface, directly enters the LSH-10 well through the surface, and then returns to the surface after reaching the bottom and connected to the collection equipment. The seepage equipment can be a pressure flow meter installed at the wellhead of the LSH-1, 3, 5, and 7 wells to test the pressure and flow at the wellheads of the LSH-1, 3, 5, and 7 wells when the LSH-0 well injects fluid.

[0159] Figure 5a Schematic diagram of the ground stress test phase provided for this application. Figure 5aAs shown, the test device for testing ground stress by hydraulic fracturing includes a high-pressure pipe, a pipeline for conveying high-pressure water, which is connected to a high-pressure pump to convey water to the test section; a packer - used to isolate the test section from other well sections, ensuring that high-pressure water only acts on the test section and preventing water from leaking to other areas; a water path conversion switch - used to control the direction of water flow, which can switch the water flow path for different tests or operations; a test section - the main test area, usually refers to a section in the wellbore, used to simulate the fracturing process of underground rocks; the borehole diameter is the diameter of the test section. In this hydraulic fracturing method, by injecting high-pressure water into the test section, when the pressure is high enough, cracks will be formed in the rock. By monitoring the formation and expansion of cracks, as well as the required pressure, the magnitude and direction of ground stress can be calculated.

[0160] In the process of testing the ground stress by hydraulic fracturing, 8 re-opening operations are performed to allow the cracks to expand better. Among them, re-opening refers to the process of re-pressurizing the cracks to reopen them after they are closed in the hydraulic fracturing experiment. Through multiple re-opening operations, we can have a deeper understanding of the whole process of crack opening, re-opening and expansion, which is helpful to obtain more accurate ground stress data. Then select multiple rounds with good consistency to comprehensively pick up the closing pressure to determine the minimum principal stress of the formation and improve the reliability of the test results.

[0161] Figure 5b This is a schematic diagram of the pressure and flow data of the test well 10 at a depth of 7.8m during the geostress test phase provided in this application. Figure 5b As shown in the figure, it includes the ground pressure change, the instantaneous flow rate of the fracturing fluid (including the water inflow and the return flow), and the cumulative flow rate of the fracturing fluid (including the cumulative water inflow and the cumulative return flow). By analyzing this figure, the opening, reopening and expansion process of the crack can be determined. For example, when the fracturing fluid flow rate suddenly drops and the ground pressure rises, it may indicate that the crack is opening or expanding; if the ground pressure drops and the flow rate recovers, it may indicate that the crack has closed; by comparing the cumulative water inflow and return flow, the permeability of the crack can be evaluated. For example, if the water inflow is much greater than the return flow, it may indicate that the crack has good permeability and can effectively absorb the fracturing fluid.

[0162] At the same time, the induced cracks under stress state can also be observed from the logging data, which mostly show the characteristics of vertical opening on the well wall. Since the clarity and objectivity of acoustic imaging logging in shallow boreholes with low temperature and low pressure are better than the impression test, the acoustic imaging logging is used to observe the orientation of the cracks. Specifically, the acoustic logging probe with a length of 1.08m was used for testing to obtain the crack imaging results at various depths. Figure 5c This is a schematic diagram of the crack morphology of the well wall of the test well 10 at a depth of 7.8m during the geostress test phase provided in this application. Figure 5cAs shown in the figure, by comparing the state of the wellbore wall before fracturing and the state of the wellbore wall after fracturing, the morphology of the wellbore wall cracks caused by fracturing is depicted. The crack angle marked in the figure can represent the angle between the crack and the well axis or other reference line, which helps to understand the spatial orientation of the crack. The distribution of cracks on the wellbore wall, such as the density and continuity of the cracks, can reflect the degree of rock fracture and the degree of development of the fracture network.

[0163] 3. Hydraulic fracturing stage:

[0164] This stage includes hydraulic fracturing experiments, microseismic data, electrical data (data collected by electromagnetic equipment), DAS fiber optic data, DSS fiber optic data, and pressure / flow data. The operating wells are fracturing well 0 and test well 8.

[0165] The fracturing truck used for fracturing is the YLC700H type fracturing truck, with a maximum displacement of 890L / min and a maximum construction fracturing pressure of 80MPa. A sand mixer is used to mix the fracturing fluid and the proppant. The fracturing fluid uses a 0.1% concentration of modified polyacrylamide drag-reducing fracturing fluid, and fluorescent powder is added as a marker for the fracturing fluid. The fracturing fluid viscosity is 13mPa·s. After flowing through the sand mixer and mixing with the proppant, it is injected into the wellhead of the LSH-0 well by the fracturing truck through a 4-inch pipeline.

[0166] Further, Figure 6 A schematic diagram of the hydraulic fracturing curve provided for this application is shown in FIG. Figure 6 As shown in the figure, the fracturing process is divided into two stages: (1) pure fracturing fluid is injected at a flow rate of 200L / min, the fracture extension pressure in the formation (i.e., injection pressure) is 1MPa, and 1.5m of fracturing fluid is used. 3 (2) Inject the mixture of fracturing fluid and proppant at a flow rate of 400L / min. The fracture extension pressure in the formation is 5.0-5.2MPa. Use 2.5m of fracturing fluid. 3 , add 150kg of proppant. During fracturing, it is necessary to collect data corresponding to microseismic stations, DAS optical fiber, DSS optical fiber, and electromagnetic equipment.

[0167] 4. Seepage test stage:

[0168] This stage includes seepage experiments, seepage injection curves, and monitoring well data. The collected data may include ① microseismic ② DAS optical fiber ③ electrical method ④ pressure ⑤ flow rate. The operating wells are fracturing well 0 and test wells 1 to 8.

[0169] Among them, the seepage experiment is used to evaluate the impact of the fracture network on fluid flow. By simulating the flow of underground fluid in the fracture network, the permeability of the fracture and the connectivity of the fracture network can be understood; the seepage injection curve reflects the relationship between the amount of fluid injected into the formation and the injection pressure within a certain period of time; the monitoring well data provides real-time information on fracture expansion and fluid flow during the fracturing process; through the comprehensive seepage experiment, injection curve and monitoring well data, the fracturing effect can be more comprehensively evaluated, including the expansion of the fracture, the permeability of the fracture network, and the distribution and flow of the fracturing fluid in the formation.

[0170] 5. Sectioning and Reconstruction Stage:

[0171] Among them, in order to observe the hydraulic fracturing crack morphology and proppant distribution characteristics, the sectioning method is used to peel off the rock mass, section it vertically layer by layer, take pictures and then collect crack morphology data to reconstruct the three-dimensional crack morphology and proppant distribution. Figure 7 Schematic diagram of the rock mass at the sectioning stage provided for this application. Figure 7 As shown, this diagram is used to illustrate the fracturing well, test well, monitoring equipment, and the fracture network inside the rock mass.

[0172] It should be noted that after data collection is completed, the hydraulic fracturing pilot method also includes:

[0173] Interpret the collected data: perform computational inversion on the data recorded by the fracturing truck, microseismic station, electromagnetic equipment, DAS fiber optic equipment, DSS fiber optic equipment and other equipment to explain the fracture formation process, fracturing fluid flow process, formation deformation process, proppant migration process, and compare with the three-dimensional fracture morphology and proppant distribution reconstructed by sectioning, propose a hydraulic fracturing process optimization plan, including the specific parameter adjustment range, construction step improvement measures, etc., and evaluate and predict the expected effect of the optimization plan to provide a scientific basis for the next round of hydraulic fracturing operations.

[0174] For example: According to the comparison and analysis results, if the fracture morphology is found to be not ideal, such as insufficient fracture extension or failure to reach the expected reservoir transformation area, consider adjusting the formulation of the fracturing fluid (such as changing the viscosity, adding additives to increase sand carrying capacity, etc.) and optimizing the fracturing construction parameters (such as increasing or decreasing the pressure, adjusting the flow rate, etc.) to improve the fracture formation effect in subsequent fracturing operations.

[0175] If proppant migration and distribution are unreasonable, such as premature deposition of proppant and uneven distribution in the fracture, optimization measures are proposed, such as improving the proppant type (such as selecting proppant with more appropriate density and better sphericity) and adjusting the change law of sand ratio during the fracturing process, to ensure that the proppant can effectively support the fracture and maintain good conductivity.

[0176] Combined with the formation deformation situation, if it is found that excessive formation deformation may affect the stability of the well or cause premature closure of fractures, a plan to control the injection speed and pressure of the fracturing fluid is proposed, or special fracturing processes (such as synchronous fracturing, clean water fracturing, etc.) are considered to reduce the risk of formation deformation while ensuring the fracturing effect.

[0177] The hydraulic fracturing pilot test method provided in the embodiment of the present application, by building a test platform that can simulate the entire process of real hydraulic fracturing in a mine, can realize a hundred-meter-level experimental data package of multiple fracturing processes such as multi-cluster initiation, multi-level support sand laying, temporary plugging fracturing, etc., that is, multi-dimensional data collected during the hydraulic fracturing pilot test; form a mesoscale fracture network multi-source data reconstruction technology, grasp the three-dimensional overall characteristics of hydraulic fractures, clarify the migration law and distribution characteristics of proppants in various types of fractures, and improve the timeliness and accuracy of fracture network characterization; based on the hundred-meter-level hydraulic fracturing experimental data package and the three-dimensional overall characteristics of fractures, an intelligent algorithm is used to optimize the fracture characteristic parameter calculation model, form an intelligent inversion method for hydraulic fracture expansion process and morphology prediction, characterize the closure law of the three-dimensional fracture network of complex reservoirs during the production process, and establish a 4D characterization technology for the entire process of three-dimensional fracture network initiation, expansion, and closure.

[0178] Figure 8 This is a schematic diagram of the structure of the hydraulic fracturing pilot test device provided in this application. Figure 8 As shown, the hydraulic fracturing pilot test device 80 provided in this embodiment includes:

[0179] The first determination module 801 is used to determine a fracturing well in a site to be tested and a plurality of test wells that satisfy a preset position relationship with the fracturing well. The site to be tested is a site that satisfies the test conditions after lithology analysis is performed on a plurality of test sites at different geographical locations;

[0180] A first testing module 802 is used to determine the ground stress state of a target testing well, wherein the location of the target testing well and the location of the fracturing well meet a first distance requirement;

[0181] The second test module 803 is used to perform a fracturing test on the fracturing well according to the ground stress state and the preset hydraulic fracturing process parameters to obtain the collected data of the detection equipment, wherein the detection equipment is a device pre-deployed in the field to be tested for collecting data during the fracturing process, and the detection equipment includes a fracturing device, a microseismic station, an electromagnetic device, an acoustic optical fiber, a strain optical fiber, and a seepage device;

[0182] The second determination module 804 is used to determine the fracture network characterization information based on the rock mass section image at the preset position of the test site, where the fracture network characterization information is used to indicate the fracture morphology and proppant distribution of the fracture formed by the hydraulic fracturing;

[0183] The data processing module 805 is used to invert the fracturing test process according to the collected data to obtain the fracturing dynamic process information, which includes the crack formation process, the fracturing fluid flow process, the formation deformation process, and the proppant migration process;

[0184] The generation module 806 is used to generate a hydraulic fracturing process optimization scheme according to the comparison result between the fracturing dynamic process information and the fracture network characterization information. The hydraulic fracturing process optimization scheme is used to optimize the preset hydraulic fracturing process parameters and hydraulic fracturing steps.

[0185] In a possible implementation, the first determining module 801 may also be used to:

[0186] Obtain lithology information of the site to be tested;

[0187] According to the lithology information and the preset drilling design parameters, drilling and coring are carried out in the site to be tested to obtain a fracturing well in the site to be tested and a plurality of test wells that meet the preset position relationship with the fracturing well.

[0188] In a possible implementation, the first determining module 801 may also be used to:

[0189] Pre-processing the cementing casing to determine the target cementing casing and the state of the target cementing casing to be installed;

[0190] If the to-be-installed status indicates that the target cementing casing meets the installation conditions, the target cementing casing is deployed to the fracturing well;

[0191] According to the preset in-pipe introduction requirements, cementing materials are introduced from the cementing casing to the bottom of the fracturing well, and according to the preset out-pipe introduction requirements, cementing materials are introduced between the cementing casing and the well wall of the fracturing well;

[0192] After the cementing material solidifies, the fracturing well is drilled from the cementing casing until the depth of the fracturing well meets the preset depth, thereby obtaining the cemented fracturing well.

[0193] In a possible implementation, the first determining module 801 may also be used to:

[0194] Obtain core samples from the fracture well and each test well;

[0195] Conduct bedding structure analysis on all core samples to determine the first test well that meets bedding distribution conditions;

[0196] Deploy the electrodes of the electromagnetic device inside the first test well, and deploy the electrodes of the electromagnetic device for testing formation resistance on the ground where the second test well is located, and the location of the second test well and the location of the fracturing well meet the second distance requirement;

[0197] Deploy the fracturing equipment on the ground at the location of the fracturing well, and connect the connecting pipe of the fracturing equipment to the cementing casing of the fracturing well;

[0198] Deploy microseismic stations on the ground and side facing surfaces of the site to be tested;

[0199] Deploy the acoustic optical fiber from the bottom of the third test well to the ground, and deploy it in the test site based on a preset ground trajectory, wherein the location of the third test well and the location of the fracturing well meet a third distance requirement;

[0200] Deploy the strain optical fiber from the bottom of the first target test well to the surface, and enter the second target test well through the ground between the first target test well and the second target test well, and return to the surface through the second target test well after the strain optical fiber is deployed to the bottom of the second target test well;

[0201] The seepage equipment is deployed at the wellhead of the second test well, and the seepage equipment includes a pressure meter and a flow meter.

[0202] In a possible implementation, the second test module 803 may also be used to:

[0203] Determine the injection parameters of the fracturing fluid and the injection parameters of the mixed fluid according to the ground stress state and the preset hydraulic fracturing process parameters, wherein the mixed fluid includes the fracturing fluid and the proppant, the fracturing fluid is the fracturing fluid added with fluorescent powder, and the proppant is the proppant added with the preset dye;

[0204] According to the fracturing fluid injection parameters and the mixed fluid injection parameters, a fracturing test is performed on the fracturing well to obtain the collected data of the detection equipment. The collected data includes the pressure, flow, microseismic event data, formation electromagnetic parameter data, acoustic wave signal, and strain data during the fracturing process.

[0205] In a possible implementation, the second determining module 804 may also be used to:

[0206] The rock mass at the preset position of the test site is sectioned to obtain a plurality of sectioned rock masses at different sectioning depths;

[0207] For each sectioned rock mass, an image of a fracture area in the sectioned rock mass is determined based on the light corresponding to the fluorescent powder;

[0208] Determine an image of a proppant region in a sectioned rock mass based on a color of a preset dye;

[0209] Based on the 3D reconstruction method, the rock mass section images corresponding to each sectioned rock mass are superimposed according to the sectioning depth to construct a 3D model;

[0210] The rock mass section image includes a fracture area image and a proppant area image, and the fracture network characterization information is determined by the three-dimensional fracture morphology and proppant distribution in the three-dimensional model.

[0211] The hydraulic fracturing pilot test device provided in this embodiment can execute the method provided in the above method embodiment. Its implementation principle and technical effect are similar, and this embodiment will not be described in detail here.

[0212] Fig. 9 This is a schematic diagram of the structure of the electronic device provided in this application. Fig. 9 As shown, the electronic device 90 provided in this embodiment includes: at least one processor 901 and a memory 902. Optionally, the device 90 further includes a communication component 903. The processor 901, the memory 902 and the communication component 903 are connected via a bus 904.

[0213] In a specific implementation process, at least one processor 901 executes the computer execution instructions stored in the memory 902, so that at least one processor 901 executes the above method.

[0214] The specific implementation process of the processor 901 can be found in the above method embodiment, and its implementation principle and technical effect are similar, so this embodiment will not be repeated here.

[0215] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the invention may be directly implemented as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0216] The memory may include a high-speed memory (Random Access Memory, RAM), and may also include a non-volatile memory (Non-volatile Memory, NVM), such as at least one disk memory.

[0217] The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, the bus in the drawings of the present application is not limited to only one bus or one type of bus.

[0218] The present application also provides a computer program product, including a computer program, which implements the above method when executed by a processor.

[0219] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When a processor executes the computer-executable instructions, the above method is implemented.

[0220] The above-mentioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general or special-purpose computer.

[0221] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (Application Specific Integrated Circuits, referred to as: ASIC). Of course, the processor and the readable storage medium can also exist in the device as discrete components.

[0222] The division of units is only a logical function division, and there may be other divisions in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other forms.

[0223] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on 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.

[0224] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0225] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0226] Those skilled in the art can understand that all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, disk or optical disk and other media that can store program codes.

[0227] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A hydraulic fracturing pilot test method, characterized in that: include: Determine a fracturing well in a site to be tested and a plurality of test wells that satisfy a preset position relationship with the fracturing well, wherein the site to be tested is a site that satisfies the test conditions after lithological analysis of a plurality of test sites at different geographical locations; Determining a ground stress state of a target test well, wherein a position of the target test well and a position of the fracturing well meet a first distance requirement; According to the ground stress state and the preset hydraulic fracturing process parameters, a fracturing test is performed on the fracturing well to obtain the collected data of the detection equipment, wherein the detection equipment is a device pre-deployed in the field to be tested for collecting data during the fracturing process, and the detection equipment includes a fracturing device, a microseismic station, an electromagnetic device, an acoustic optical fiber, a strain optical fiber, and a seepage device; Based on the rock mass section image at the preset position of the test site, determining the fracture network characterization information, wherein the fracture network characterization information is used to indicate the fracture morphology and proppant distribution of the fracture formed by the hydraulic fracturing; Inverting the fracturing test process according to the collected data to obtain fracturing dynamic process information, wherein the fracturing dynamic process information includes crack formation process, fracturing fluid flow process, formation deformation process, and proppant migration process; According to the comparison result between the fracturing dynamic process information and the fracture network characterization information, a hydraulic fracturing process optimization scheme is generated, and the hydraulic fracturing process optimization scheme is used to optimize the preset hydraulic fracturing process parameters and hydraulic fracturing steps.

2. The method according to claim 1, characterized in that The step of determining a fracturing well in a site to be tested and a plurality of test wells that satisfy a preset position relationship with the fracturing well comprises: Obtaining lithology information of the site to be tested; According to the lithology information and preset drilling design parameters, drilling and coring are performed in the site to be tested to obtain a fracturing well in the site to be tested and a plurality of test wells that satisfy a preset positional relationship with the fracturing well.

3. The method according to claim 2, characterized in that The method further comprises: Pre-processing the cementing casing to determine the target cementing casing and the state of the target cementing casing to be installed; If the to-be-installed state indicates that the target cementing casing meets the installation conditions, deploying the target cementing casing to the fracturing well; According to the preset in-pipe introduction requirements, the cementing material is introduced from the cementing casing to the bottom of the fracturing well, and according to the preset out-pipe introduction requirements, the cementing material is introduced between the cementing casing and the well wall of the fracturing well; After the cementing material solidifies, the fracturing well is drilled from the cementing casing until the depth of the fracturing well meets a preset depth, thereby obtaining a cemented fracturing well.

4. The method according to claim 3, characterized in that Before determining the ground stress state of the target test well, the method further includes: Obtaining core samples from the fracturing well and each test well; Conduct bedding structure analysis on all core samples to determine the first test well that meets bedding distribution conditions; Deploy the electrodes of the electromagnetic device inside the first test well, and deploy the electrodes of the electromagnetic device for testing formation resistance on the ground where the second test well is located, wherein the location of the second test well and the location of the fracturing well meet a second distance requirement; Deploy a fracturing device on the ground where the fracturing well is located, and connect a connecting pipe of the fracturing device to a cementing casing of the fracturing well; Deploy microseismic stations on the ground and side open surfaces of the site to be tested; Deploy the acoustic optical fiber from the bottom of a third test well to the ground, and deploy it in the site to be tested based on a preset ground track, wherein the location of the third test well and the location of the fracturing well meet a third distance requirement; Deploy the strain optical fiber from the bottom of the first target test well to the surface, and enter the second target test well through the ground between the first target test well and the second target test well, and return to the surface through the second target test well after the strain optical fiber is deployed to the bottom of the second target test well; A seepage device is deployed at the wellhead of the second test well, wherein the seepage device includes a pressure meter and a flow meter.

5. The method according to claim 1, characterized in that The method of performing a fracturing test on the fracturing well according to the ground stress state and the preset hydraulic fracturing process parameters to obtain the collected data of the detection equipment includes: Determining fracturing fluid injection parameters and mixed fluid injection parameters according to the ground stress state and preset hydraulic fracturing process parameters, wherein the mixed fluid includes fracturing fluid and proppant, the fracturing fluid is a fracturing fluid with fluorescent powder added, and the proppant is a proppant with a preset dye added; According to the fracturing fluid injection parameters and the mixed fluid injection parameters, a fracturing test is performed on the fracturing well to obtain collected data of the detection equipment, wherein the collected data includes pressure, flow, microseismic event data, formation electromagnetic parameter data, acoustic wave signals, and strain data during the fracturing process.

6. The method according to claim 5, characterized in that The determining of the fracture network characterization information based on the rock mass section image at the preset position of the site to be tested includes: The rock mass at the preset position of the test site is sectioned to obtain a plurality of sectioned rock masses at different sectioning depths; For each sectioned rock mass, based on the light corresponding to the fluorescent powder, determine a crack region image in the sectioned rock mass; Determining a proppant region image in the sectioned rock mass based on the color of the preset dye; Based on the 3D reconstruction method, the rock mass section images corresponding to each sectioned rock mass are superimposed according to the sectioning depth to construct a 3D model; The rock mass section image includes the fracture area image and the proppant area image, and the fracture network characterization information is determined by the three-dimensional fracture morphology and proppant distribution in the three-dimensional model.

7. A hydraulic fracturing pilot test device, characterized in that: include: A first determination module is used to determine a fracturing well in a site to be tested and a plurality of test wells that satisfy a preset position relationship with the fracturing well, wherein the site to be tested is a site that satisfies the test conditions after lithological analysis of a plurality of test sites at different geographical locations; A first testing module, used to determine the ground stress state of a target testing well, wherein the location of the target testing well and the location of the fracturing well meet a first distance requirement; A second testing module is used to perform a fracturing test on the fracturing well according to the ground stress state and preset hydraulic fracturing process parameters to obtain data collected by a detection device, wherein the detection device is a device pre-deployed in the site to be tested for collecting data during the fracturing process, and the detection device includes a fracturing device, a microseismic station, an electromagnetic device, an acoustic optical fiber, a strain optical fiber, and a seepage device; A second determination module is used to determine fracture network characterization information based on a rock mass section image at a preset position of a site to be tested, wherein the fracture network characterization information is used to indicate fracture morphology and proppant distribution conditions formed by hydraulic fracturing; A data processing module, for inverting the fracturing test process according to the collected data to obtain fracturing dynamic process information, wherein the fracturing dynamic process information includes crack formation process, fracturing fluid flow process, formation deformation process, and proppant migration process; A generation module is used to generate a hydraulic fracturing process optimization plan based on the comparison result between the fracturing dynamic process information and the fracture network characterization information, and the hydraulic fracturing process optimization plan is used to optimize the preset hydraulic fracturing process parameters and hydraulic fracturing steps.

8. An electronic device, characterized in that: include: Memory, processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory, so that the processor performs the method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 6 when executed by a processor.

10. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 1 to 6 when being executed by a processor.

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