Evaluation method for plugging formation fractures

Abstract

This invention provides a method for evaluating leakage plugging in formation fractures. The method includes: acquiring three-dimensional fracture data of the formation fractures in the drilling fluid leakage area; creating a simulated metal fracture based on the three-dimensional fracture data; determining that the simulated metal fracture meets preset requirements; applying a preset confining pressure to the simulated metal fracture that meets the preset requirements; injecting a plugging slurry with a preset formula into the simulated metal fracture under the preset confining pressure; determining that a sealing body is formed in the simulated metal fracture; acquiring the plugging pressure and leakage rate of the sealing body; and evaluating the plugging effect of the plugging slurry based on the plugging pressure and leakage rate. The method is simple to operate, can realistically reproduce formation fractures, and effectively improves the leakage plugging effect of formation fractures.

Description

Technical Field

[0001] This invention relates to the field of oil and gas field exploration and development technology, and specifically to a method for evaluating the plugging of formation fractures. Background Technology

[0002] Well leakage is the phenomenon of drilling fluid flowing into the formation during drilling. Well leakage not only consumes a large amount of drilling fluid and prolongs the drilling cycle, but improper handling can also lead to complex situations such as well collapse, blowout, and stuck pipe, and even cause wellbore abandonment, resulting in serious economic losses. Moreover, as oil and gas exploration and development expands to deep, ultra-deep, and deep-sea areas, geological conditions become more demanding, and well leakage problems become more prominent. Therefore, it is necessary to select appropriate plugging materials and plugging processes through plugging experiments to achieve the purpose of sealing the formation and safe drilling. However, the fracture models used in the existing plugging evaluation methods for formation fractures still have a large gap with the actual fracture leakage channels, resulting in poor field application effects of the selected plugging materials and inability to effectively plug formation fractures. Summary of the Invention

[0003] The purpose of this invention is to provide a method for evaluating the sealing of formation fractures. This method is simple to operate, can accurately reproduce formation fractures, and effectively improves the sealing effect of formation fractures.

[0004] To achieve the above objectives, embodiments of the present invention provide a method for evaluating leakage plugging in formation fractures, the method comprising:

[0005] Acquire three-dimensional fracture data of formation fractures in the drilling fluid loss area;

[0006] Create a metal simulation crack based on 3D crack data;

[0007] Confirm that the simulated metal cracks meet the preset requirements;

[0008] Apply a preset confining pressure to the simulated metal crack that meets the preset requirements;

[0009] Inject a pre-formulated plugging grout into a simulated metal crack under a pre-set confining pressure;

[0010] Determine the formation of a sealing body in a simulated metal crack;

[0011] Obtain the pressure bearing capacity and leakage rate of the sealing body;

[0012] The effectiveness of the plugging grout is evaluated based on the pressure resistance and leakage rate.

[0013] In embodiments of the present invention, obtaining three-dimensional fracture data of formation fractures in the drilling fluid loss area includes:

[0014] 3D scanning of formation fractures is performed to obtain three-dimensional fracture data.

[0015] In embodiments of the present invention, determining that the simulated metal crack meets preset requirements includes:

[0016] Determine the relative error of the joint roughness coefficient between simulated metal fractures and formation fractures;

[0017] Determine the relative error of tortuosity between simulated metal fractures and formation fractures;

[0018] The relative error of joint roughness coefficient and the relative error of tortuosity determine whether the simulated crack in the metal meets the preset requirements.

[0019] In embodiments of the present invention, determining the relative error of the joint roughness coefficient between simulated metal fractures and formation fractures includes:

[0020] Determine the roughness coefficient of the first joint in the simulated metal crack;

[0021] Determine the roughness coefficient of the second joint in the formation fracture;

[0022] The relative error of the joint roughness coefficient is determined based on the roughness coefficient of the first joint and the roughness coefficient of the second joint.

[0023] In embodiments of the present invention, determining the relative error in tortuosity between simulated metal fractures and formation fractures includes:

[0024] Determine the first set of tortuosity values ​​for the simulated metal crack;

[0025] Determine the second set of tortuosity values ​​for formation fractures;

[0026] The relative error of tortuosity is determined based on the first and second tortuosity sets.

[0027] In embodiments of the present invention, determining whether a simulated metal crack meets preset requirements based on a first joint roughness coefficient, a first set of tortuosity coefficients, a relative error of the joint roughness coefficient, and a relative error of tortuosity includes:

[0028] Determine whether the roughness coefficient of the first joint is within the first preset range;

[0029] Determine whether all values ​​in the first set of tortuosity degrees are within the second preset range;

[0030] Determine whether the relative error of the joint roughness coefficient does not exceed the preset relative error of the joint roughness coefficient;

[0031] Determine whether the relative error of tortuosity does not exceed the preset relative error of tortuosity;

[0032] If the first joint roughness coefficient is determined to be within a first preset range, all values ​​in the first tortuosity set are within a second preset range, the relative error of the joint roughness coefficient does not exceed the preset relative error of the joint roughness coefficient, and the relative error of the tortuosity does not exceed the preset relative error of the tortuosity, then the simulated metal crack is determined to meet the preset requirements, wherein the preset relative error of the joint roughness coefficient and the preset relative error of the tortuosity do not exceed 2%.

[0033] In an embodiment of the present invention, the first preset range is 40-60.

[0034] In an embodiment of the present invention, the second preset range is 1-1.2.

[0035] In embodiments of the present invention, the evaluation of the plugging effect of the plugging slurry based on the plugging pressure and leakage amount includes:

[0036] Determine whether the leak-sealing pressure is greater than the preset leak-sealing pressure;

[0037] If the pressure required to stop the leak is determined to be greater than the preset pressure required to stop the leak, determine whether the leakage rate is less than the preset leakage rate.

[0038] If the leakage is less than the preset leakage, the sealing effect of the sealing grout is deemed acceptable.

[0039] In embodiments of the present invention, the material of the simulated metal crack includes at least one of stainless steel, mold steel, titanium alloy, aluminum alloy, cobalt-chromium alloy, and copper alloy.

[0040] The above technical solution involves acquiring three-dimensional fracture data of formation fractures in the drilling fluid leakage area, then creating a metal-simulated fracture based on the three-dimensional fracture data to accurately depict the surface morphology of the formation fractures. A plugging experiment is then conducted using the metal-simulated fracture that meets preset requirements to form a plug. The plugging effect is evaluated based on the plugging pressure and leakage rate. This plugging evaluation method selects a plugging slurry that can effectively plug actual formation fractures, significantly improving the plugging effect.

[0041] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0042] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0043] Figure 1 This is a flowchart illustrating the leak-stopping evaluation method in an embodiment of the present invention;

[0044] Figure 2 This is a three-dimensional model diagram of the simulated metal crack in an embodiment of the present invention;

[0045] Figure 3 This is a schematic diagram of the composition of the leak-sealing experimental system in an embodiment of the present invention;

[0046] Figure 4 This is a schematic diagram of the pressure bearing curve in an embodiment of the present invention.

[0047] Explanation of reference numerals in the attached figures

[0048] 1. Hydraulic pump 2. Injection pump

[0049] 3. Press 4. Leak-sealing simulation module

[0050] 5. Intermediate container 6. Pressure sensor

[0051] 7 Measuring cylinder 8 Computer Detailed Implementation

[0052] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0053] This invention provides a method for evaluating leakage plugging in formation fractures. This method is applicable to formations other than mudstone, such as carbonate formations, sandstone formations, and conglomerate formations. Specifically, for example... Figure 1 As shown, the leak-sealing evaluation method includes the following steps, wherein:

[0054] Step S101: Obtain three-dimensional fracture data of formation fractures in the drilling fluid loss area.

[0055] In one embodiment of the present invention, step S101: obtaining three-dimensional fracture data of formation fractures in the drilling fluid loss area further includes:

[0056] 3D scanning of formation fractures is performed to obtain three-dimensional fracture data.

[0057] Specifically, this embodiment uses sandstone formation fractures in the Bozi area as an example for leakage plugging evaluation. The formation fractures in this area are extremely well-developed, with a linear density reaching up to 7.6 fractures / meter, and fracture widths ranging from 0.1 to 3 mm. The fractures are predominantly unfilled or partially filled, with some fractures in an open state. When acquiring three-dimensional fracture data for this area, operators first obtain core samples from the well, and then use a 3D scanner to perform 3D scanning of the formation fractures in the core samples to obtain high-precision three-dimensional fracture data, which is then used to accurately depict the surface morphology of the formation fractures.

[0058] The 3D scanner used in this embodiment is a high-precision 3D line laser measuring instrument, which adopts ultra-high precision measurement of 3200 points / profile. The 3D scanner is also equipped with a shape processing algorithm filter to minimize the impact of numerical fluctuations caused by interference.

[0059] Step S102: Create a metal simulation crack based on the three-dimensional crack data.

[0060] Specifically, after obtaining the three-dimensional fracture data, the data is first imported into MaterialiseMagics data processing software for processing. In this embodiment, the flow direction of the plugging fluid in the simulated metal fracture is denoted as the x-direction, the direction perpendicular to the flow direction is denoted as the y-direction, and the direction perpendicular to the xy-plane is denoted as the z-direction. Then, the processed three-dimensional fracture data is imported into Autodesk Maya modeling software to establish a three-dimensional model of the formation fracture (e.g., ...). Figure 2 (as shown); then, based on the above three-dimensional model, a 3D printer was used to create a simulated metal crack.

[0061] Because the rock cores extracted from the well are brittle and have poor wear resistance, they are easily damaged during repeated experiments, which will change the morphology of the fractures and prevent the experiments from being repeated. However, in this embodiment, 3D scanning printing technology is used to perfectly reproduce the rock fractures after hydraulic fracturing using high-strength materials. This can effectively restore the real fracture morphology of the formation and the strength can meet the standards for repeated experiments. This allows the printed metal simulated fractures to be tested repeatedly. Furthermore, 3D scanning technology can obtain data on the surface morphology of the formation fractures, providing a basis for subsequent calculations of the surface morphology of the formation fractures.

[0062] In one embodiment of the present invention, the material of the metal simulated crack includes at least one of stainless steel, mold steel, titanium alloy, aluminum alloy, cobalt-chromium alloy and copper alloy. Further, in this embodiment, the material of the metal simulated crack is preferably stainless steel (such as 15-5PH type stainless steel), which has excellent mechanical properties, such as good toughness and high strength, as well as good wear resistance and temperature resistance.

[0063] Step S103: Determine that the simulated metal crack meets the preset requirements.

[0064] In one embodiment of the present invention, step S103: determining that the simulated metal crack meets the preset requirements further includes steps S201-S203, wherein:

[0065] S201: Determine the relative error of the joint roughness coefficient between the simulated metal fracture and the formation fracture.

[0066] In one embodiment of the present invention, S201: determining the relative error of the joint roughness coefficient between the simulated metal fracture and the formation fracture further includes steps S301-S303, wherein:

[0067] Step S301: Determine the roughness coefficient of the first joint in the simulated metal crack;

[0068] Step S302: Determine the roughness coefficient of the second joint of the formation fracture;

[0069] Step S303: Determine the relative error of the joint roughness coefficient based on the first joint roughness coefficient and the second joint roughness coefficient.

[0070] Specifically, when calculating the joint roughness coefficient of a crack, the root mean square (RMS) of the relative height of the crack surface must first be calculated, and then the joint roughness coefficient can be calculated based on the RMS of the relative height. Furthermore, to calculate the RMS of the relative height, the three-dimensional coordinates at position (i, j) on the crack surface, as well as the side lengths of the crack in the x and y directions, must be determined. All of this data can be obtained by performing a 3D scan of the crack using a 3D scanner. The RMS of the relative height Z2 can then be calculated using the following formula:

[0071]

[0072] Where Z2 is the root mean square of the relative height; L x L represents the side length of the crack along the x-axis, in mm. y x represents the side length of the crack along the y-axis, in mm; i,j Let x be the x-axis coordinate of the crack location (i,j); i+1,j+1 Let x be the x-axis coordinate of the crack location (i+1, j+1); x i,j+1 Let x be the x-axis coordinate of the crack at position (i, j+1); i+1,j Let x be the x-coordinate of the crack at position (i+1, j); y be the x-coordinate of the crack at position (i+1, j). i,j Let y be the y-coordinate of the crack at location (i,j); i+1,j+1 Let y be the y-coordinate of the crack at position (i+1, j+1); i,j+1 Let y be the y-coordinate of the crack at position (i, j+1); i+1,j Let z be the y-coordinate of the crack at position (i+1, j); z i+1,j+1 Let z be the z-axis coordinate of the crack location (i+1, j+1); i,j+1 Let z be the z-axis coordinate of the crack at position (i, j+1); i+1,j Let (i, j) be the z-axis coordinate of the crack at position (i+1, j).

[0073] The joint roughness coefficient can be calculated using the following formula:

[0074] JRC=32.2+32.471gZ2 (2)

[0075] Where JRC is the joint roughness coefficient.

[0076] Substituting the three-dimensional crack data obtained by the 3D scanner from the simulated metal crack into formula (1) and formula (2), the first joint roughness coefficient JRC1 can be calculated; substituting the three-dimensional crack data obtained by the 3D scanner from the formation crack into formula (1) and formula (2), the second joint roughness coefficient JRC2 can be calculated; and then the relative error of the joint roughness coefficient is calculated based on the first joint roughness coefficient JRC1 and the second joint roughness coefficient JRC2.

[0077] S202: Determine the relative error of tortuosity between the simulated metal fracture and the formation fracture.

[0078] In one embodiment of the present invention, S202: determining the relative error of tortuosity between the simulated metal fracture and the formation fracture further includes steps S401-S403, wherein:

[0079] Step S401: Determine the first set of tortuosity values ​​for the simulated metal crack;

[0080] Step S402: Determine the second set of tortuosity values ​​for formation fractures;

[0081] Step S403: Determine the relative error of tortuosity based on the first set of tortuosity and the second set of tortuosity.

[0082] Specifically, the tortuosity set in this embodiment includes the tortuosity of the crack along the x-direction, the tortuosity of the crack along the y-direction, and the average tortuosity of the crack surface. The above-mentioned multiple different types of tortuosity can be calculated by the following formula:

[0083]

[0084] Where, τ x z is the tortuosity of the crack along the x-direction; m is the number of profile lines in the x-direction (the profile line is the value obtained by dividing the scanner's scanning length by the scanner's precision); Δx is the scanning interval of the scanner in the x-direction (in this embodiment, Δx is preferably 0.1 mm); z i,j Let l be the z-axis coordinate of the crack location (i, j); x The length of the profile line in the x-direction is in mm.

[0085]

[0086] Where, τ y denoted as y, where n is the tortuosity of the crack along the y direction; n is the number of profile lines along the y direction; Δy is the scanning interval of the scanner along the y direction (in this embodiment, Δy is preferably 0.1 mm); l y The length of the profile line in the y-direction is in mm.

[0087]

[0088] Where τ is the average tortuosity of the crack surface.

[0089] Substituting the data related to the metal simulated fracture and the formation fracture in the above formulas into formulas (3)-(5), we can calculate the values ​​of the first tortuosity set and the second tortuosity set. Then, we can calculate the second error based on the values ​​of the first tortuosity set and the second tortuosity set.

[0090] In this embodiment, the relevant parameters of the metal simulated fracture and the formation fracture are shown in Table 1, which include the root mean square of relative height, joint roughness coefficient, fracture tortuosity along the x-direction, fracture tortuosity along the y-direction, average tortuosity of the fracture surface, relative error of tortuosity, relative error of joint roughness coefficient, and relative error of tortuosity.

[0091] Table 1. Relevant parameters of simulated metal fractures and formation fractures.

[0092]

[0093] S203: Based on the first joint roughness coefficient, the first tortuosity set, the relative error of the joint roughness coefficient, and the relative error of the tortuosity, determine whether the simulated metal crack meets the preset requirements.

[0094] In one embodiment of the present invention, S203: determining whether the simulated metal crack meets the preset requirements based on the first joint roughness coefficient, the first tortuosity set, the relative error of the joint roughness coefficient, and the relative error of the tortuosity, further includes steps S501-S505, wherein:

[0095] Step S501: Determine whether the roughness coefficient of the first joint is within the first preset range;

[0096] Step S502: Determine whether each value in the first set of tortuosity degrees is within the second preset range;

[0097] Step S503: Determine whether the relative error of the joint roughness coefficient does not exceed the preset relative error of the joint roughness coefficient;

[0098] Step S504: Determine whether the relative error of tortuosity does not exceed the preset relative error of tortuosity;

[0099] Step S505: If the first joint roughness coefficient is determined to be within the first preset range, all values ​​in the first tortuosity set are within the second preset range, the relative error of the joint roughness coefficient does not exceed the preset relative error of the joint roughness coefficient, and the relative error of the tortuosity does not exceed the preset relative error of the tortuosity, then the simulated metal crack is determined to meet the preset requirements, wherein the preset relative error of the joint roughness coefficient and the preset relative error of the tortuosity do not exceed 2%.

[0100] Specifically, when determining whether the simulated metal crack meets the preset requirements, multiple relevant parameters of the simulated metal crack, including the first joint roughness coefficient, the relative error of the preset joint roughness coefficient, and the relative error of the preset tortuosity, must be evaluated. Only when all of the above parameters meet the requirements can the simulated metal crack be determined to meet the preset requirements. It can realistically reproduce the surface morphology of underground stratum cracks, and the leakage evaluation results obtained through it will be more realistic. The selected leakage sealing slurry can also achieve better leakage sealing effect in actual application. Among them, the first preset range is 40-60, the second preset range is 1-1.2, and the relative error of the preset joint roughness coefficient and the relative error of the preset tortuosity do not exceed 2% (furthermore, in this embodiment, the relative error of the preset joint roughness coefficient and the relative error of the preset tortuosity are preferably both not exceeding 1.5%). If any of the above parameters does not meet the requirements, it is determined that the simulated metal crack does not meet the preset requirements. At this time, the above operation steps should be repeated until the simulated metal crack meets the preset requirements.

[0101] Step S104: Apply a preset confining pressure to the simulated metal crack that meets the preset requirements.

[0102] Specifically, after confirming that the simulated metal cracks meet the preset requirements, a crack sealing test system needs to be used to conduct a sealing test on the simulated metal cracks, such as... Figure 3 As shown, the crack sealing test system in this embodiment includes a hydraulic pump 1, an injection pump 2, a press 3, a sealing simulation module 4, an intermediate container 5, a pressure sensor 6, a measuring cylinder 7, and a computer 8. During the experiment, steel plates of a certain thickness are installed on both sides of the simulated metal crack according to the experimental requirements. This allows for adjustment of the crack width. The simulated metal crack is then placed in the sealing simulation module 4, and a preset confining pressure is applied to the upper and lower sides of the simulated metal crack. The preset confining pressure in this embodiment can be set according to the actual situation.

[0103] Step S105: Inject a pre-formulated plugging grout into a simulated metal crack under a pre-set confining pressure.

[0104] In this embodiment, there are multiple preset formulas for the sealing grout. It is necessary to conduct sealing tests on the sealing grouts with different preset formulas one by one. Taking the sealing test of a 1mm crack width as an example, the preset formula of the sealing grout is water + 6% bentonite + 0.06% caustic soda + 0.1% CMC-AV. KGD and QSD are selected as sealing materials. Among them, the component of QSD is hard nut shell, which is crushed and sorted to form granules and flakes; the component of KGD is calcite, which has the characteristics of high strength and easy acid solubility.

[0105] After step S104 is completed, pour the sealant, which is uniformly mixed with the sealant material, into the intermediate container 5, connect the pipeline equipment, turn on the injection pump 2, select the constant flow displacement mode, the sealant simulation module 4 is equipped with a heating jacket, and after adjusting the temperature of the sealant simulation module 4 to 150℃ through the heating jacket, the injection pump 2 will gradually start injecting at a constant flow rate of 30ml / min.

[0106] Step S106: Determine the formation of a sealing body in the simulated metal crack.

[0107] As the sealing grout flows through the simulated metal crack, it gradually forms a seal. However, the pressure bearing capacity of this pressure-bearing body changes with the continuous injection of the sealing grout, eventually leading to complete rupture. The pressure bearing capacity of the seal before rupture is the maximum pressure bearing capacity. This maximum pressure bearing capacity can be detected by pressure sensor 6. Then, sealing grout is injected again onto the ruptured seal to re-seal the simulated metal crack until a new seal is formed. In this embodiment, pressure sensor 6 sends the pressure detection results to computer 8, and the plotting software on computer 8 can plot a pressure bearing curve (e.g., ...) based on the pressure detection results. Figure 4 As shown in the figure, it is convenient for the experimenters to observe; compare the pressure detection result of pressure sensor 6 with the preset pressure (such as 10Mpa). If the pressure detection result exceeds the preset pressure, it indicates that the blockage body has been formed.

[0108] Step S107: Obtain the sealing pressure and leakage amount of the sealing body.

[0109] In this embodiment, the pressure sensor 6 is used to obtain the sealing pressure of the sealing body, the metering cylinder 7 is used to collect the leakage of sealing slurry during the experiment, and the leakage amount can be obtained by reading the scale on the metering cylinder 7.

[0110] Step S108: Evaluate the sealing effect of the sealing grout based on the sealing pressure and leakage rate.

[0111] In one embodiment of the present invention, step S108: evaluating the plugging effect of the plugging grout based on the plugging pressure and leakage amount further includes steps S601-S602, wherein:

[0112] Step S601: Determine whether the leak-sealing pressure is greater than the preset leak-sealing pressure;

[0113] Step S601: If the pressure to stop the leak is determined to be greater than the preset pressure to stop the leak, determine whether the leakage amount is less than the preset leakage amount;

[0114] Step S601: If the leakage is less than the preset leakage, the sealing effect of the sealing grout is deemed qualified.

[0115] Specifically, when evaluating the plugging effect of the plugging grout, it is necessary to determine the plugging pressure and leakage amount generated by different preset plugging grouts in the plugging experiment. In addition, it is only necessary to further compare the leakage amount if the plugging body has sufficient plugging pressure; otherwise, the plugging body will not be able to achieve a good plugging function. Therefore, in this embodiment, the leakage amount is judged to be qualified only when the plugging pressure is greater than the preset plugging pressure. When the leakage amount is less than the preset leakage amount, the plugging effect of the plugging grout is determined to be qualified, and the plugging grout can be applied to the actual sealing of formation fractures.

[0116] Furthermore, if the sealing effect of various pre-formulated sealing grouts is satisfactory, their respective leakage amounts can be compared, and the pre-formulated sealing grout with the lowest leakage amount can be selected for practical application. This helps to reduce the amount of sealing grout used while meeting the sealing requirements, thus saving energy.

[0117] Furthermore, in this embodiment, after step S106, the pressure of the leak-sealing test system can be released, the pipeline and intermediate container 5 can be disassembled, and the leak-sealing simulation module 4 can be opened to observe the sealing condition of the sealing body, such as the tightness of the sealing body, the sealing position, and the bridging method of the particles (such as single particle bridging, double particle bridging, or multi-particle bridging).

[0118] This invention provides a method for evaluating leakage plugging in formation fractures. It involves acquiring three-dimensional fracture data of the formation fractures in the drilling fluid leakage area, then creating a metal-simulated fracture based on the three-dimensional fracture data to accurately depict the surface morphology of the formation fractures. A leakage plugging experiment is then conducted using the metal-simulated fracture that meets preset requirements to form a plug. The plugging effect is evaluated based on the plugging pressure and leakage rate of the plug. This method selects a plugging slurry that can effectively plug actual formation fractures, significantly improving the leakage plugging effect.

[0119] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0120] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0121] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0122] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0123] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0124] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0125] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information by any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient media, such as modulated data signals and carrier waves.

[0126] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0127] The above are merely embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A method for evaluating the plugging of formation fractures, characterized in that, The leak-sealing evaluation method includes: Acquire three-dimensional fracture data of formation fractures in the drilling fluid loss area; A metal simulation crack is created based on the aforementioned three-dimensional crack data; Determine the relative error of the joint roughness coefficient between the simulated metal fracture and the formation fracture; Determine the relative error of tortuosity between the simulated metal fracture and the formation fracture; Based on the relative error of the joint roughness coefficient and the relative error of the tortuosity, it is determined that the simulated metal crack meets the preset requirements; A preset confining pressure is applied to the simulated metal crack that meets the preset requirements; Inject a sealing grout with a preset formula into a simulated metal crack under the preset confining pressure; It was determined that a sealing body was formed in the simulated metal crack; Obtain the sealing pressure and leakage amount of the sealing body; The effectiveness of the sealing slurry is evaluated based on the sealing pressure and the leakage rate.

2. The method for evaluating the plugging of formation fractures according to claim 1, characterized in that, The acquisition of three-dimensional fracture data of formation fractures in the drilling fluid loss area includes: A 3D scan of the formation fractures was performed to obtain the three-dimensional fracture data.

3. The method for evaluating the plugging of formation fractures according to claim 1, characterized in that, The relative error in determining the joint roughness coefficient between the simulated metal fracture and the formation fracture includes: Determine the first joint roughness coefficient of the simulated metal crack; Determine the second joint roughness coefficient of the formation fracture; The relative error of the joint roughness coefficient is determined based on the first joint roughness coefficient and the second joint roughness coefficient.

4. The method for evaluating the plugging of formation fractures according to claim 3, characterized in that, The determination of the relative error in tortuosity between the simulated metal fracture and the formation fracture includes: Determine the first set of tortuosity values ​​for the simulated metal crack; Determine the second set of tortuosity values ​​for the formation fractures; The relative error of tortuosity is determined based on the first set of tortuosity values ​​and the second set of tortuosity values.

5. The method for evaluating the plugging of formation fractures according to claim 4, characterized in that, The step of determining whether the simulated metal crack meets the preset requirements based on the first joint roughness coefficient, the first tortuosity set, the relative error of the joint roughness coefficient, and the relative error of the tortuosity includes: Determine whether the roughness coefficient of the first joint is within a first preset range; Determine whether each value in the first set of tortuosity degrees is within the second preset range; Determine whether the relative error of the joint roughness coefficient does not exceed the preset relative error of the joint roughness coefficient; Determine whether the relative error of tortuosity does not exceed the preset relative error of tortuosity; If the first joint roughness coefficient is within the first preset range, all values ​​in the first tortuosity set are within the second preset range, the relative error of the joint roughness coefficient does not exceed the preset relative error of the joint roughness coefficient, and the relative error of the tortuosity does not exceed the preset relative error of the tortuosity, then the simulated metal crack is determined to meet the preset requirements, wherein the preset relative error of the joint roughness coefficient and the preset relative error of the tortuosity both do not exceed 2%.

6. The method for evaluating the plugging of formation fractures according to claim 5, characterized in that, The first preset range is 40-60.

7. The method for evaluating leakage plugging in formation fractures according to claim 6, characterized in that, The second preset range is 1-1.

2.

8. The method for evaluating leakage plugging in formation fractures according to claim 1, characterized in that, The evaluation of the sealing effect of the sealing slurry based on the sealing pressure and the leakage amount includes: Determine whether the pressure required for sealing the leak is greater than the preset pressure required for sealing the leak; If the pressure required to stop the leak is determined to be greater than the preset pressure required to stop the leak, it is then determined whether the leakage amount is less than the preset leakage amount. If the leakage amount is less than the preset leakage amount, the sealing effect of the sealing slurry is determined to be qualified.

9. The method for evaluating the plugging of formation fractures according to any one of claims 1-8, characterized in that, The material of the simulated metal crack includes at least one of stainless steel, mold steel, titanium alloy, aluminum alloy, cobalt-chromium alloy, and copper alloy.

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