Method and device for determining hydraulic fracturing perforation azimuth information

Abstract

The present invention discloses a method and device for determining the azimuth information of hydraulic fracturing perforation, which relates to the technical field of oilfield development. The method includes: obtaining a plurality of core rock samples of a specified shale reservoir; conducting acoustic emission tests and paleomagnetic tests on the core rock samples to determine the azimuth and magnitude of the maximum and minimum horizontal principal stresses and the azimuth of natural fractures; establishing a true three-dimensional hydraulic fracturing model by using the azimuth and magnitude of the maximum and minimum horizontal principal stresses and the azimuth of natural fractures; conducting hydraulic fracturing on the hydraulic fracturing specimen by using the true three-dimensional hydraulic fracturing model to determine the azimuth of the hydraulic fracture, the horizontal pressure difference of the hydraulic fracturing, and the approach angle; analyzing the azimuth of the hydraulic fracture, the horizontal pressure difference of the hydraulic fracturing, and the approach angle according to the azimuth and magnitude of the maximum and minimum horizontal principal stresses and the azimuth of natural fractures, and determining the hydraulic fracturing perforation azimuth according to the analysis results. The present invention can improve the accuracy of the determined perforation parameters.

Description

Technical Field

[0001] The present invention relates to the technical field of oilfield development, and in particular to a method and device for determining the azimuth information of hydraulic fracturing perforation. Background Art

[0002] This section aims to provide background or context for the embodiments of the present invention described in the claims. The description herein is not admitted to be prior art merely because it is included in this section.

[0003] Different from conventional gas reservoirs, the porosity of shale matrix is usually less than 10%, and the permeability is less than 1 mD. Its reservoir physical properties are poor. Therefore, shale has always been considered as a caprock blocking oil and gas migration, rather than a reservoir or source rock. The extremely low matrix permeability of shale reservoirs requires that only by means of large-scale artificial hydraulic fracturing technology can industrial gas flow be achieved.

[0004] The widespread natural fractures and microcracks are the basic characteristics of shale reservoirs. The hydraulic fracturing process is to pump fracturing fluid into the formation by a high-pressure pump, and transfer a large enough pressure to the reservoir through the fracturing fluid to cause the initiation, penetration and expansion of microcracks. In view of the complexity of shale reservoirs themselves and the high input cost of fracturing construction, it is very necessary to design fracture and perforation parameters for shale gas wells before hydraulic fracturing. Since the current research and understanding of the propagation behavior of hydraulic fractures in shale reservoirs are still in the primary stage, it is difficult to tackle key problems. Unreasonable design of fracturing segmented perforation will lead to unsatisfactory post-fracture natural gas production capacity. Some perforation clusters may be in a state where they cannot be opened due to high stress. During the fracturing process of these perforation clusters, the fracturing fluid intake is low, and the contribution to production capacity after fracturing construction is low. Therefore, there is an urgent need for a reasonable perforation determination scheme at present to improve the accuracy of the determined perforation parameters, perform efficient perforation positioning on the reservoir, ensure the success rate of hydraulic fracturing, and improve the oilfield development effect. Summary of the Invention

[0005] The embodiments of the present invention provide a method for determining the azimuth information of hydraulic fracturing perforation, which is used to improve the accuracy of the determined perforation parameters, perform efficient perforation positioning on the reservoir, ensure the success rate of hydraulic fracturing, and improve the oilfield development effect. The method includes:

[0006] Obtain a plurality of core rock samples of a specified shale reservoir;

[0007] Perform acoustic emission tests on the plurality of core rock samples to determine the azimuth information and magnitude of the maximum horizontal principal stress and the azimuth information and magnitude of the minimum horizontal principal stress of the specified shale reservoir;

[0008] Perform paleomagnetic tests on the plurality of core rock samples to determine the azimuth information of the natural fractures of the specified shale reservoir;

[0009] Establish a true three-dimensional hydraulic fracturing model by using the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures;

[0010] Use the true three-dimensional hydraulic fracturing model to perform hydraulic fracturing on the pre-obtained hydraulic fracturing specimens to obtain hydraulic fractures, and determine the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approaching angle;

[0011] Analyze the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approaching angle according to the azimuth information and magnitude of the maximum horizontal principal stress, the magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures, and determine the hydraulic fracturing perforation azimuth information according to the analysis results.

[0012] The embodiment of the present invention also provides a device for determining the hydraulic fracturing perforation azimuth information, which is used to improve the accuracy of the determined perforation parameters, perform efficient perforation positioning on the reservoir, ensure the success rate of hydraulic fracturing, and improve the oilfield development effect. The device includes:

[0013] A core acquisition module for acquiring multiple core samples of a specified shale reservoir;

[0014] An acoustic emission test module for performing acoustic emission tests on multiple core samples to determine the azimuth information and magnitude of the maximum horizontal principal stress and the azimuth information and magnitude of the minimum horizontal principal stress of the specified shale reservoir;

[0015] A paleomagnetic test module for performing paleomagnetic tests on multiple core samples to determine the azimuth information of natural fractures in the specified shale reservoir;

[0016] A model construction module for establishing a true three-dimensional hydraulic fracturing model by using the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures;

[0017] A fracturing data processing module for using the true three-dimensional hydraulic fracturing model to perform hydraulic fracturing on the pre-obtained hydraulic fracturing specimens to obtain hydraulic fractures, and determining the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approaching angle;

[0018] A perforation azimuth determination module for analyzing the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approaching angle according to the azimuth information and magnitude of the maximum horizontal principal stress, the magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures, and determining the hydraulic fracturing perforation azimuth information according to the analysis results.

[0019] An embodiment of the present invention further provides a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the method for determining the hydraulic fracturing perforation azimuth information described above is implemented.

[0020] An embodiment of the present invention further provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the method for determining the hydraulic fracturing perforation azimuth information described above is implemented.

[0021] An embodiment of the present invention further provides a computer program product including a computer program, and when the computer program is executed by a processor, the method for determining the hydraulic fracturing perforation azimuth information described above is implemented.

[0022] In an embodiment of the present invention, a plurality of core rock samples of a specified shale reservoir are obtained; acoustic emission tests are performed on the plurality of core rock samples to determine the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress of the specified shale reservoir; paleomagnetic tests are performed on the plurality of core rock samples to determine the azimuth information of the natural fractures of the specified shale reservoir; a true three-dimensional hydraulic fracturing model is established using the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of the natural fractures; the true three-dimensional hydraulic fracturing model is used to perform hydraulic fracturing on a pre-obtained hydraulic fracturing specimen to obtain a hydraulic fracture, and the azimuth information of the hydraulic fracture, the horizontal pressure difference of the hydraulic fracturing, and the approaching angle are determined; the azimuth information of the hydraulic fracture, the horizontal pressure difference of the hydraulic fracturing, and the approaching angle are analyzed based on the azimuth information and magnitude of the maximum horizontal principal stress, the magnitude of the minimum horizontal principal stress, and the azimuth information of the natural fractures, and the hydraulic fracturing perforation azimuth information is determined according to the analysis results. In this way, through acoustic emission tests and paleomagnetic tests, the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of the natural fractures of the shale reservoir are determined. Then, after simulating hydraulic fracturing on the hydraulic fracturing specimen using the true three-dimensional hydraulic fracturing model, the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of the natural fractures of the shale reservoir are used to analyze the hydraulic fracturing data to guide the determination of the hydraulic fracturing perforation azimuth information, improve the accuracy of the determined perforation parameters, make the reservoir perforation positioning more efficient, and thus ensure the success rate of hydraulic fracturing and improve the oilfield development effect. Description of the Drawings

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings. In the drawings:

[0024] Figure 1 It is a flowchart of a method for determining the orientation information of hydraulic fracturing perforations provided in an embodiment of the present invention;

[0025] Figure 2 It is a schematic diagram of the position of the marking line of the core rock sample provided in an embodiment of the present invention;

[0026] Figure 3 It is a schematic diagram of six directions for obtaining the stress components of the core rock sample provided in an embodiment of the present invention;

[0027] Figure 4 It is a characteristic curve graph of acoustic emission provided in an embodiment of the present invention;

[0028] Figure 5 It is a schematic diagram of the coordinate system for paleomagnetic core orientation measurement provided in an embodiment of the present invention;

[0029] Figure 6 It is a schematic diagram of the direction cosine of the unit vector on each axis in a rectangular coordinate system provided in an embodiment of the present invention;

[0030] Figure 7 It is a schematic diagram of the stress loading direction during hydraulic fracturing of a true three-dimensional hydraulic fracturing model provided in an embodiment of the present invention;

[0031] Figure 8 It is a curve graph of the water pressure and time of hydraulic fracturing provided in an embodiment of the present invention;

[0032] Figure 9 It is a schematic diagram of a device for determining the orientation information of hydraulic fracturing perforations provided in an embodiment of the present invention;

[0033] Figure 10 It is a schematic diagram of a computer device provided in an embodiment of the present invention. Detailed implementation manners

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer and more understandable, the following will further elaborate on the embodiments of the present invention in conjunction with the drawings. Herein, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but do not limit the present invention.

[0035] In the description of this specification, terms such as "including", "comprising", "having", "containing", etc. are all open-ended terms, meaning including but not limited to. The description with reference to terms such as "one embodiment", "one specific embodiment", "some embodiments", "for example", etc. means that the specific features, structures or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. The order of steps involved in each embodiment is used to schematically illustrate the implementation of the present application, and the order of steps is not limited and can be adjusted appropriately as needed.

[0036] Through research, it is found that the microcracks or natural fractures already developed in the shale reservoir provide a good material basis for the formation of the fracturing fracture network. Microcracks are precisely its important mesoscopic characteristics and also the root cause of the nonlinear mechanical behavior of rock masses. Currently, the research on the stress distribution problem around horizontal wellbores mainly considers the influence of factors such as wellbore pressure, original formation pressure, fracturing fluid seepage, and perforation, while ignoring the influence of natural fractures in the reservoir. The fracture initiation modes of fractured reservoirs are essentially different from those of conventional reservoirs, and there are cases such as initiation from the rock matrix, shear initiation along fractures, and tensile initiation. The magnitude of the initiation pressure will be directly affected by the fracture initiation mode. Therefore, conducting research on the initiation mechanism of perforated horizontal wells in fractured reservoirs and finding reasonable initiation laws are the prerequisite guarantees for the success of horizontal well fracturing construction and have important significance for increasing the oil and gas production of the reservoir.

[0037] During the hydraulic fracturing process, people are increasingly aware of the importance of mastering the direction of natural fractures. Hydraulic fracturing can not only increase the production of old oilfields but also is one of the important technical means to achieve the effective development of unconventional oil and gas. Whether hydraulic fracturing can form complex fractures is an important criterion for evaluating its success. There are many influencing factors for whether hydraulic fractures can form complex fractures, such as subjective factors in engineering and objective factors in the reservoir. Among them, natural fractures have an important impact on the morphology, propagation and extension direction, etc. of hydraulic fractures. Therefore, studying the direction of natural fractures has very important practical significance for reservoir stimulation, the determination of the well row direction of development wells, and the selection of well patterns.

[0038] In view of the above research, the embodiment of the present invention proposes a method and device for determining the perforation azimuth information of hydraulic fracturing. It can first determine the direction of in-situ stress, then determine the direction of natural fractures, and guide the determination of perforation parameters for each section of the well through the direction of in-situ stress and the direction of natural gas fractures, thereby improving the accuracy of the determined perforation parameters, performing efficient perforation positioning on the reservoir, ensuring the success rate of hydraulic fracturing, and improving the oilfield development effect.

[0039] Figure 1 The flowchart of a method for determining the azimuth information of hydraulic fracturing perforation provided by an embodiment of the present invention. The method includes the following steps:

[0040] Step 101: Obtain a plurality of core samples of a specified shale reservoir;

[0041] Step 102: Conduct acoustic emission tests on the plurality of core samples to determine the azimuth information and magnitude of the maximum horizontal principal stress, and the azimuth information and magnitude of the minimum horizontal principal stress of the specified shale reservoir;

[0042] Step 103: Conduct paleomagnetic tests on the plurality of core samples to determine the azimuth information of the natural fractures of the specified shale reservoir;

[0043] Step 104: Establish a true three-dimensional hydraulic fracturing model by using the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of the natural fractures;

[0044] Step 105: Use the true three-dimensional hydraulic fracturing model to perform hydraulic fracturing on a pre-acquired hydraulic fracturing specimen to obtain hydraulic fractures, and determine the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approaching angle;

[0045] Step 106: Analyze the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approaching angle according to the azimuth information and magnitude of the maximum horizontal principal stress, the magnitude of the minimum horizontal principal stress, and the azimuth information of the natural fractures, and determine the azimuth information of the hydraulic fracturing perforation according to the analysis results.

[0046] In the embodiment of the present invention, a plurality of core samples of a specified shale reservoir are obtained; acoustic emission tests are performed on the plurality of core samples to determine the azimuth information and magnitude of the maximum horizontal principal stress, and the azimuth information and magnitude of the minimum horizontal principal stress of the specified shale reservoir; paleomagnetic tests are performed on the plurality of core samples to determine the azimuth information of natural fractures in the specified shale reservoir; a true three-dimensional hydraulic fracturing model is established by using the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures; the true three-dimensional hydraulic fracturing model is used to perform hydraulic fracturing on a pre-obtained hydraulic fracturing specimen to obtain hydraulic fractures, and the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approach angle are determined; the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approach angle are analyzed according to the azimuth information and magnitude of the maximum horizontal principal stress, the magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures, and the hydraulic fracturing perforation azimuth information is determined according to the analysis results. In this way, through acoustic emission tests and paleomagnetic tests, the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures of the shale reservoir are determined. Then, after simulating hydraulic fracturing on the hydraulic fracturing specimen by using the true three-dimensional hydraulic fracturing model, the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures of the shale reservoir are used to analyze the hydraulic fracturing data, guide the determination of the hydraulic fracturing perforation azimuth information, improve the accuracy of the determined perforation parameters, make the reservoir perforation positioning more efficient, and thus ensure the success rate of hydraulic fracturing and improve the oilfield development effect.

[0047] The following Figure 1 describes in detail the method for determining the hydraulic fracturing perforation azimuth information shown.

[0048] In step 101 above, a plurality of core samples of a specified shale reservoir can be obtained.

[0049] Specifically, a plurality of core samples of a specified shale reservoir can be obtained first. Each core sample is processed as follows:

[0050] On the cylindrical surface of the full-size core sample, a marking line parallel to the axis of the core column is drawn (the marking line is a common reference line for acoustic emission tests and paleomagnetic measurement methods). The position of the marking line is as Figure 2 shown, and the direction of the marking line is extended to the cross-section of the core sample. The full-size core sample is processed into a standard sample with a diameter of 25 mm and a height of 25 mm. On the end face of each standard sample, a straight line passing through the axis parallel to the marking line is marked.

[0051] In step 102 above, acoustic emission tests can be performed on the plurality of core samples to determine the azimuth information and magnitude of the maximum horizontal principal stress, and the azimuth information and magnitude of the minimum horizontal principal stress of the specified shale reservoir.

[0052] In one embodiment, the above azimuth information may include an azimuth angle, which can be used to represent direction and position.

[0053] Specifically, in acoustic emission testing, when a core sample is loaded, microcracks inside the rock expand. When the pressure on the rock reaches its pre-existing maximum stress, acoustic emission occurs. When the load is continuously applied and the pressure on the rock is greater than its pre-existing maximum stress, the existing cracks further expand and penetrate, and new cracks are generated, accompanied by a large amount of acoustic emission activity. Due to the inhomogeneity of the core samples, the stress level values obtained from testing different core samples at the same location and in the same direction will also be different. Therefore, as many samples as possible are needed for testing in each direction. After the experiment, the load value can be determined according to the Kaiser effect characteristic points selected for each sample, and the stress value can be calculated from the stress area of the core sample. The average value of multiple core samples in the same direction is the stress component in that direction. Specifically: the stress components mainly refer to the stress components in six directions of the core sample, namely X, Y, Z, X45°Y, Y45°Z, Z45°X. The six directions of the core sample are as Figure 3 shown. By calculating using the loads of the Kaiser effect characteristic points of the core samples in 6 spatial directions, the magnitudes and azimuths of the principal stresses at the sampling points are finally obtained. The load of each core sample is determined according to its Kaiser effect characteristic point, the stress is calculated from the stress area of the core sample, and the average value of multiple core samples is the stress test value in that direction. Based on this, the magnitude and azimuth of the principal stress are obtained. For the data processing of the acoustic emission test, first, the stress value corresponding to the Kaiser effect characteristic point of each core sample needs to be calculated. The specific calculation process is as follows:

[0054] Step 1: Calculate the stress σ corresponding to the Kaiser effect characteristic point of each core sample according to formula (1) K :

[0055] σ K = 10P K / F (1)

[0056] In the formula: σ K is the stress at the Kaiser effect characteristic point, MPa; P K is the load corresponding to the Kaiser effect characteristic point, kN; F is the cross-sectional area of the core sample, cm 2 .

[0057] Step 2: Based on the stress corresponding to the Kaiser effect characteristic point of each core sample, calculate the stress components in six directions of X, Y, Z, X45°Y, Y45°Z, and Z45°X according to formula (2):

[0058]

[0059] Where: σ X , σ Y , σ Z , σ X45°Y , σ Y45°Z , σ Z45°X are the stress components in six directions of X, Y, Z, X45°Y, Y45°Z, and Z45°X; σ K，X , σ K，Y , σ K，Z , σ K，X45°Y , σ K，Y45°Z , σ K，Z45°X are the stresses corresponding to the Kaiser effect characteristic points of the core rock samples in six directions of X, Y, Z, X45°Y, Y45°Z, and Z45°X; n is the number of core rock samples in each direction.

[0060] Step 3: Solve for the principal stresses:

[0061] According to the stress components in six directions of σ X , σ Y , σ Z , σ X45°Y , σ Y45°Z , σ Z45°X , use Equation (3) to calculate the maximum, intermediate, and minimum principal stresses σ1, σ2, and σ3 in space, that is, obtained from the cubic equation:

[0062] σ 3 -J1σ 2 +J2σ - J3 = 0 (3)

[0063] Obtain each principal stress, that is

[0064]

[0065] Where:

[0066]

[0067]

[0068] J1, J2, and J3 are three invariants of the stress state, which are respectively:

[0069]

[0070] τ XY , τ YZ , τ ZX are respectively

[0071]

[0072] Where: σ X, σ Y , σ Z , σ X45°Y , σ Y45°Z , σ Z45°X These six stress components are the stress components determined through the acoustic emission test.

[0073] Step 4: Solve for the azimuth angle of the principal stress:

[0074] The direction cosines of the angles between the directions of the principal stress and the coordinate axes X, Y, and Z are mi, ni, and li respectively, which can be calculated according to formula (5):

[0075]

[0076] Wherein,

[0077]

[0078] The dip angle and azimuth angle of the principal stress can be calculated by formula (6):

[0079]

[0080] Where: α i is the angle between the principal stress σ i and the XOY plane, that is, the dip angle (positive for elevation angle, negative for depression angle); β i is the angle between the projection of the principal stress σ i on the XOY plane and the X-axis, that is, the azimuth angle (positive for counterclockwise, negative for clockwise).

[0081] According to the above method, the magnitude and azimuth information of the maximum horizontal principal stress, and the magnitude and azimuth information of the minimum horizontal principal stress of the specified shale reservoir can be obtained.

[0082] It should be noted that accurately selecting the Kaiser effect characteristic point is the key to the method of using acoustic emission and the Kaiser effect to test the in-situ stress of core rock samples. During the acoustic emission test process, the instrument automatically records basic acoustic emission parameters such as the arrival time, duration, number of events, ring count, and energy of the acoustic emission. When determining the acoustic emission Kaiser effect characteristic point of each core rock sample, the acoustic emission energy and ring count are selected as the test parameters. Figure 4 (a) and (b) in are the acoustic emission characteristic curves of a core rock sample, where the a curve is the relationship curve between the load and time, the b curve is the relationship curve between the acoustic emission ring count and time, and the c curve is the relationship curve between the cumulative acoustic emission energy and time. Analyzing the variation characteristics of the two curves, the starting point of the step corresponds to the acoustic emission signal mutation point, that is, the Kaiser effect characteristic point of this specimen.

[0083] In the above step 103, paleomagnetic tests can be carried out on multiple core samples to determine the azimuth information of natural fractures in a specified shale reservoir.

[0084] During specific implementation, as Figure 5 shown, it is a schematic diagram of the coordinate system for paleomagnetic core orientation measurement. Paleomagnetic core orientation measurement determines the north pole azimuth based on the horizontal component, uses a right-handed coordinate system, and the positive direction of the Z-axis is downward. The magnetic declination D reflects the geographic north pole azimuth angle. Since the X-axis passes through the marking line and D is the angle between the horizontal component H and the X-axis, D determines the geographic azimuth of the marking line.

[0085] Perform magnetization intensity and magnetic cleaning detection tests on the test standard samples (the test standard samples obtained after processing the core samples in step 101). The test standard samples generally need to undergo alternating demagnetization and thermal demagnetization by a magnetometer (a small rotation and superconducting magnetometer), and are measured and processed in segments according to the steps. The magnetic declination measured by using the viscous remanent magnetization orientation can be directly converted into the geographic north pole direction (in the case where the inclination angle of the drilled core sample is very small), without considering complex processes such as geological age, local magnetic declination, and using geological outcrops for measurement and comparison. The magnetic inclination (vertical vector) depends on the local geographic latitude, and the relationship between this latitude and the magnetic inclination is formula (7):

[0086] tgI = 2tgL (7)

[0087] In the formula: I is the magnetic inclination of the viscous remanent magnetization, unit (°); L is the local geographic latitude, unit (°).

[0088] If the latitude of the sampling location is known, within a relevant temperature range (below 350 °C), the viscous remanent magnetization can be separated by screening the vector method. There is always an inclination angle close to the value of the geomagnetic axial dipole (GAD) magnetic field, and then the vector declination is corrected to determine the azimuth information of the natural fracture (i.e., the original azimuth of the core sample).

[0089] To determine the average direction of the core remanent magnetization vector, paleomagnetic tests are carried out on multiple core samples. Generally, the Fisher statistical method is used to obtain the test results of a group of samples. In Fisher statistics, the algebraic method is generally used to find the average direction of the vector. Assume that N samples are randomly selected from the population composed of all samples, and the inclination angle and declination of the characteristic remanent magnetization direction are measured as I i , and D i (i = 1, 2, 3...). In the rectangular coordinate system, the direction cosine of the unit vector on each axis is as Figure 6 shown, and the formula is:

[0090] X = CosD·COSI Y = SinD·COSI Z = SinI

[0091] The direction cosines of the characteristic remanent magnetic vectors of each sample are added to obtain the length and average direction cosines of the resultant vector:

[0092]

[0093]

[0094] The declination of this average direction and inclination are respectively:

[0095]

[0096] The declination and inclination herein characterize the direction of the average remanent magnetic vector finally measured for a group of rock samples.

[0097] In the above step 104, a true three-dimensional hydraulic fracturing model can be established by using the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures.

[0098] In one embodiment, step 104 may specifically include:

[0099] The azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures are used as the true triaxial loading mode information of the true three-dimensional hydraulic fracturing model.

[0100] Specifically in implementation, the true three-dimensional hydraulic fracturing model may be a large-size true three-dimensional hydraulic fracturing model. In the embodiments of the present invention, the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures are used as the true triaxial loading mode information of the true three-dimensional hydraulic fracturing model, that is, the stress loading direction when the true three-dimensional hydraulic fracturing model performs hydraulic fracturing.

[0101] As Figure 7 shown, it is a schematic diagram of the stress loading direction when a true three-dimensional hydraulic fracturing model provided by the embodiments of the present invention performs hydraulic fracturing. Similar materials are used to wrap the original rock sample as the fracturing specimen. During the specimen preparation process, the rock sample is first pre-placed in the mold, and then similar materials are poured around it. The specimen size is 600mm×600mm×450mm( Figure 7)。The top end of the fracturing pipe is externally threaded and is sealingly connected to the high-pressure rubber hose for fracturing fluid. The specimens are cured for 10 days to fully gelatinize and bond the contact surface between the similar material and the rock specimen. After the specimens are cured, a hydraulic fracturing test is carried out. According to the test conditions of constant stress and variable fracturing fluid displacement, a large-scale true triaxial coal and rock hydraulic fracturing simulation test is carried out. The 5 letters in the figure are respectively the maximum horizontal principal stress σ1, the vertical stress σ2, the minimum horizontal principal stress σ3, σ 11 and σ 12 is the pressure applied by the maximum horizontal principal stress at the front end of the three-dimensional model, σ 21 and σ 22 is the pressure applied by the maximum horizontal principal stress at the front end of the three-dimensional model.

[0102] In the above step 105, the above true three-dimensional hydraulic fracturing model can be used to perform hydraulic fracturing on the pre-acquired hydraulic fracturing specimens to obtain hydraulic fractures, and determine the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approach angle.

[0103] Specifically, when implementing, after performing hydraulic fracturing on the pre-acquired hydraulic fracturing specimens, hydraulic fractures can be obtained, and based on the data recorded during the hydraulic fracturing process, the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approach angle can be determined.

[0104] Specifically, the horizontal pressure difference of hydraulic fracturing refers to the pressure difference required for rock fracture during hydraulic fracturing, indicating the minimum pressure difference required to form fractures in the rock layer, usually expressed in pressure units (such as Pascal). The approach angle of hydraulic fracturing refers to the angle between the injected hydraulic fracturing fluid and the rock layer. It represents the angle between the injection direction of the fluid and the rock layer, which affects the propagation direction of the fluid in the rock and the formation mode of the fractures.

[0105] Calculating the horizontal pressure difference and the approach angle requires considering multiple parameters, including the mechanical properties of the rock, the characteristics of the fracturing fluid, and the stress state of the underground rock, etc. The specific calculation method can adopt numerical simulation or empirical formulas.

[0106] A commonly used method for calculating the horizontal pressure difference is to estimate it using the Hubbert-Rubey formula based on the stress state of the underground rock layer and the formation thickness: △σ=(0.87×σ v )+(0.46×σ h ), where, σ v represents the vertical stress (common unit: psi), σ h represents the horizontal stress (common unit: psi).

[0107] Calculating the approaching angle requires combining the injection parameters of the hydraulic fracturing fluid and the mechanical properties of the rock. Generally, the selection of the approaching angle should consider factors such as the stress state of the rock, the fracture properties of the rock strata, and the expected fracture morphology. The Berryman formula is used to calculate the approaching angle: applicable to heterogeneous, non-linear elastic rocks, and the approaching angle (θ) is calculated by the following formula: θ = arcsin(β / (α + β)), where α and β represent the ratio of the injection velocity of the hydraulic fracturing fluid to the shear wave velocity, respectively.

[0108] During specific implementation, the azimuth information of the hydraulic fracture can be directly obtained through the hydraulic fracturing characteristic curve and the test stress loading curve of the hydraulic fracturing specimen.

[0109] In step 106 above, the azimuth information of the hydraulic fracture, the horizontal pressure difference of the hydraulic fracturing, and the approaching angle can be analyzed based on the azimuth information and magnitude of the maximum horizontal principal stress, the magnitude of the minimum horizontal principal stress, and the azimuth information of the natural fracture. The azimuth information of the hydraulic fracturing perforation is determined according to the analysis results.

[0110] In one embodiment, step 106 above can specifically include:

[0111] When any of the following conditions is met, the azimuth information of the hydraulic fracturing perforation is determined as: the direction of the azimuth angle is the same as the direction of the natural fracture, and the position is passing through the natural fracture:

[0112] The direction of the maximum horizontal principal stress and the direction of the hydraulic fracture are perpendicular, and the approaching angle is within the first preset range;

[0113] The direction of the maximum horizontal principal stress and the direction of the hydraulic fracture are the same, and the approaching angle is within the second preset range;

[0114] The direction of the hydraulic fracture and the direction of the natural fracture are perpendicular, and the ratio of the magnitude of the minimum horizontal principal stress to the magnitude of the maximum horizontal principal stress is greater than the preset magnitude ratio.

[0115] In another embodiment, step 106 above can specifically further include:

[0116] When the horizontal pressure difference is the first preset threshold and the approaching angle is the second preset threshold, or when the horizontal pressure difference is less than the third preset threshold and the approaching angle is less than the fourth preset threshold, the azimuth information of the hydraulic fracturing perforation is determined not to intersect the natural fracture according to the azimuth information of the natural fracture.

[0117] In specific implementation, the first preset range, the second preset range, the preset size ratio, the first preset threshold, the second preset threshold, the third preset threshold, the fourth preset threshold, and the above-mentioned multiple conditions can all be obtained by analyzing the post-fracturing data in advance using a true three-dimensional hydraulic fracturing model through multiple hydraulic fracturing experiments.

[0118] In specific implementation, the hydraulic fracturing sample may refer to: a hydraulic fracturing sample of 300mm×300mm×300mm processed from a shale outcrop obtained from the site after hydraulic cutting. The specific steps of hydraulic fracturing using the true three-dimensional hydraulic fracturing model may be:

[0119] 1) Process the shale outcrop into a standard hydraulic fracturing specimen and record its bedding distribution morphology.

[0120] 2) Drill a simulated wellbore inside the hydraulic fracturing sample and lower the slotted casing. The slotted casing uses a high-strength steel pipe with an outer diameter of 20 mm and an inner diameter of 15 mm. Put the prepared hydraulic fracturing sample into the true triaxial loading chamber of the true three-dimensional hydraulic fracturing model. At the position of 135-165 mm, 1.5 mm wide hydraulic channels are symmetrically cut. The bottom end is closed, and the upper end is built-in with threads to seal and connect with the hydraulic fracturing pump pipeline. The casing is sealed with a high-strength adhesive to simulate the horizontal well of the shale gas reservoir.

[0121] Two acoustic emission probes are placed on each diagonal of the four end faces of the hydraulic fracturing sample to effectively monitor the cracking information of the internal cracks of the hydraulic fracturing sample; red tracers are added to the fracturing fluid to facilitate observation of the hydraulic fracturing channel by dissecting the sample after the test.

[0122] 3) A true triaxial physical model testing machine with a true three-dimensional hydraulic fracturing model is used to simulate the loading of three-dimensional geostress conditions.

[0123] 4) Define a preset range value for the perforation azimuth and perform perforation within this range.

[0124] 5) Start the hydraulic fracturing pump pressure system and acoustic emission monitoring system, and the computer will collect data synchronously in real time.

[0125] 6) After the fracturing test is completed, the hydraulic fracturing pump pressure and the acoustic emission system are stopped, and the true triaxial physical model testing machine is smoothly unloaded to 0.

[0126] 7) Disassemble the hydraulic fracturing specimen, directly observe and record each loading surface of the hydraulic fracturing specimen, and take photos with a digital camera.

[0127] 8) After the hydraulic fracturing is completed, the red tracer inside the hydraulic fracturing is described, and the pump pressure curve and acoustic emission monitoring data are analyzed to complete the comprehensive analysis of the cracking morphology of shale hydraulic fracturing, such as Figure 8As shown in (a) and (b), it is a curve graph of water pressure and time for hydraulic fracturing.

[0128] As Figure 8 As shown in (a), after the fracturing fluid fills the primary fractures, the hydraulic fractures begin to extend. First, they extend along the primary fractures. When the fracturing fluid continues to be injected into the fracturing pipe, the water pressure curve starts to fluctuate up and down, accompanied by the generation and extension of new fractures. When the fracturing fluid is continuously pumped into the fracturing pipe, the new fractures continue to extend in the hydraulic fracturing. Due to the existence of natural fractures with different degrees of development in the hydraulic fracturing, the fracturing fluid continuously connects the natural fractures. After the fracturing fluid encounters the natural fractures, the net water pressure in the fractures is different, resulting in the up and down fluctuation of the water pressure curve. After a certain stage of reciprocation, with the continuous pumping of the fracturing fluid, the hydraulic fractures extend in the rock sample. After several fracturings, the displacement of the fracturing fluid is increased (twice the displacement of the fracturing fluid in the first fracturing), and the water pressure curve is as Figure 8 shown in (b). As Figure 8 can be seen from (b), the water pressure mainly fluctuates within a certain range. The maximum pressure value is significantly greater than the water pressure peak value before the variable displacement. Different perforation azimuth angles can obtain different water pressure curves. The best perforation azimuth angle is determined according to the maximum pressure value and the range of the curve and the number of reciprocating cycles. The more the number of reciprocations of the curve, the more hydraulic fractures are formed by perforation fracturing, and the more obvious the effect of reaching the effective seepage channel. At this time, the perforation angle is the best until the hydraulic fractures extend to the surface of the hydraulic fracturing sample, and the fracturing fluid flows out from the hydraulic fracture channel penetrating the sample, and the test ends, and the fracturing pump is shut down.

[0129] According to the above analysis, the direction of the fractures during hydraulic fracturing is affected by stress. When the horizontal stress difference is large (such as 5 - 10 MPa), it is difficult to form a complex fracture network. The extension direction of the hydraulic fractures is always parallel to the direction of the maximum horizontal principal stress of the formation or perpendicular to the fault strike, and the fractures are along the direction of the minimum principal stress.

[0130] In this way, through the above analysis, the following conclusions can be drawn:

[0131] 1. When the direction of the maximum horizontal principal stress is perpendicular to the direction of the hydraulic fractures and the approaching angle is in the range of 5° - 30° (the first preset range), or the direction of the maximum horizontal principal stress is the same as the direction of the hydraulic fractures and the approaching angle is in the range of 60° - 90° (the second preset range), or the direction of the hydraulic fractures is perpendicular to the direction of the natural fractures and the ratio of the magnitude of the minimum horizontal principal stress to the magnitude of the maximum horizontal principal stress is greater than 0.75 (the preset magnitude ratio), the perforation direction should be along and through the direction of the natural fractures (that is, the direction of the hydraulic fracturing perforation is the same as the direction of the natural fractures, and the position is to pass through the natural fractures);

[0132] 2. When the horizontal pressure difference is the first preset threshold and the approaching angle is the second preset threshold, that is, the horizontal pressure difference and the approaching angle value when the hydraulic fracture formed by hydraulic fracturing is captured by natural fractures, and it fails to open or pass through the natural fractures and cannot form an effective seepage channel, the perforation direction should avoid natural fractures as much as possible (that is, the azimuth information of hydraulic fracturing perforation is not intersecting with natural fractures).

[0133] 3. When the horizontal pressure difference is less than the third preset threshold and the approaching angle is less than the fourth preset threshold, that is, the pressure difference and the approaching angle value when natural fractures are opened by hydraulic fracturing fractures, forming larger fractures but failing to form a connected seepage channel, the perforation direction should avoid natural fractures as much as possible (that is, the azimuth information of hydraulic fracturing perforation is not intersecting with natural fractures).

[0134] Regarding the above 2 and 3, if the perforation direction cannot avoid natural fractures, the fracturing pressure can be increased to open the natural fractures.

[0135] In this way, through the above method, accurate hydraulic fracturing perforation azimuth information can be obtained.

[0136] In one embodiment, after the above step 105, it may further include:

[0137] Using numerical simulation methods to calculate the productivity data of hydraulic fracturing perforation azimuth information;

[0138] If the productivity data meets the preset productivity conditions, the hydraulic fracturing perforation azimuth information is valid;

[0139] If the productivity difference does not meet the preset productivity conditions, re-determine the hydraulic fracturing perforation azimuth information.

[0140] Specifically in implementation, it is possible to construct, fracture, and model natural fractures. Use petrel geological modeling software, utilize well logging data to identify horizon information, establish a geological section (draw well section), use seismic data to establish geological horizons and identify fault openings, utilize drilling horizon interpretation data to identify horizons, import and analyze fracture parameters: Import the interpretation results of pre-acquired reservoir fracture data (fracture distribution and fracture intensity), analyze the data to determine the fracture distribution of each single well in each horizon and the fracture intensity distribution of the reservoir; Combine the fracture distribution map, and classify natural fractures according to the azimuth angle of the fractures, so as to build different types of fractures inside the reservoir to generate and process different types of fractures. Fracture parameters: Control the fracture generation density according to the pre-obtained fracture strength parameters of the fractures, and set important parameters such as the direction, size, aperture, and permeability of each type of fracture previously divided. Under the same sedimentary environment, different lithological structures usually have different fracture distributions, so the fracture generation can be controlled by the lithofacies modeling results.

[0141] Use Kinetix for hydraulic fracture network simulation. Specifically, import the well area data of the shale reservoir obtained in advance, select and set the geographical location of the work area, and import the wellhead coordinate data, wellbore trajectory, logging data, and logging interpretation data (including Techlog interpretation data) results in the work area; well structure, set the Kinetix fracturing well, and select the built-in casing and tubing according to the casing and tubing composition of each well in the work area and load the logging data of each construction well.

[0142] In this way, according to the data of the above geological modeling, calculate the productivity data of the hydraulic fracturing perforation azimuth information through numerical simulation, and compare the productivity data of the hydraulic fracturing perforation azimuth information with the historical actual productivity of the actually obtained oilfield cases in advance. If there is an actual increase in productivity of 5%-15%, the hydraulic fracturing perforation azimuth information is effective; otherwise, it is necessary to re-determine the hydraulic fracturing perforation azimuth information.

[0143] In this way, when the hydraulic fracturing perforation azimuth information is effective, parameters such as the length of the shot cluster, the perforation density of each perforation cluster (restricted flow method), and the hole diameter can be set according to the actual construction requirements (logging curve, reservoir quality (RQ), completion quality (CQ)), as well as the above-mentioned hydraulic fracturing perforation azimuth information, and multi-fracture transformation of the horizontal well can be carried out: separate the horizontal well into multiple sections through downhole tools, perform multi-cluster perforation on each section according to the hydraulic fracturing perforation azimuth information, then inject the working fluid with a high-pressure pump, open multiple fractures at the hole, and add proppants to support the fractures; transform each section step by step to form a large-volume complex fracture network and achieve the purpose of increasing production.

[0144] In the embodiments of the present invention, a device for determining hydraulic fracturing perforation azimuth information is also provided, as described in the following embodiments. Since the principle of the device for solving problems is similar to the method for determining hydraulic fracturing perforation azimuth information, the implementation of the device can refer to the implementation of the method for determining hydraulic fracturing perforation azimuth information, and the repeated parts will not be elaborated.

[0145] As Figure 9 shown, it is a schematic diagram of a device for determining hydraulic fracturing perforation azimuth information provided by an embodiment of the present invention. The device may include:

[0146] A core acquisition module 901, configured to acquire multiple core samples of a specified shale reservoir;

[0147] An acoustic emission test module 902, configured to perform acoustic emission tests on multiple core samples to determine the azimuth information and magnitude of the maximum horizontal principal stress and the azimuth information and magnitude of the minimum horizontal principal stress of the specified shale reservoir;

[0148] A paleomagnetic test module 903, configured to perform paleomagnetic tests on multiple core samples to determine the azimuth information of natural fractures in the specified shale reservoir;

[0149] A model construction module 904, configured to establish a true three-dimensional hydraulic fracturing model by using the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures;

[0150] A fracturing data processing module 905, configured to perform hydraulic fracturing on a pre-acquired hydraulic fracturing specimen by using the true three-dimensional hydraulic fracturing model to obtain hydraulic fractures, and determine the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approaching angle;

[0151] A perforation azimuth determination module 906, configured to analyze the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approaching angle according to the azimuth information and magnitude of the maximum horizontal principal stress, the magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures, and determine the hydraulic fracturing perforation azimuth information according to the analysis result.

[0152] In one embodiment, the model construction module may specifically be configured to:

[0153] Use the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures as the true triaxial loading mode information of the true three-dimensional hydraulic fracturing model.

[0154] In one embodiment, the azimuth information may be an azimuth angle, and the azimuth angle may be used to represent a direction and a position.

[0155] In one embodiment, the perforation azimuth determination module may specifically be configured to:

[0156] When any one of the following conditions is satisfied, determine that the azimuth information of the hydraulic fracturing perforation is: the direction of the azimuth angle is the same as the direction of the natural fracture, and the position is passing through the natural fracture:

[0157] The direction of the maximum horizontal principal stress is perpendicular to the direction of the hydraulic fracture, and the approaching angle is within a first preset range;

[0158] The direction of the maximum horizontal principal stress is the same as the direction of the hydraulic fracture, and the approaching angle is within a second preset range;

[0159] The direction of the hydraulic fracture is perpendicular to the direction of the natural fracture, and the ratio of the magnitude of the minimum horizontal principal stress to the magnitude of the maximum horizontal principal stress is greater than a preset magnitude ratio.

[0160] In one embodiment, the perforation azimuth determination module may further be configured to:

[0161] When the horizontal pressure difference is the first preset threshold and the approaching angle is the second preset threshold, or when the horizontal pressure difference is less than the third preset threshold and the approaching angle is less than the fourth preset threshold, determine that the orientation information of the hydraulic fracturing perforation does not intersect with the natural fracture according to the orientation information of the natural fracture.

[0162] In one embodiment, it may further include a perforation orientation verification module, which is used after the perforation orientation determination module analyzes the orientation information and magnitude of the maximum horizontal principal stress, the magnitude of the minimum horizontal principal stress, and the orientation information of the natural fracture, and determines the orientation information of the hydraulic fracturing perforation according to the analysis result:

[0163] Use numerical simulation methods to calculate the productivity data of the hydraulic fracturing perforation orientation information;

[0164] If the productivity data meets the preset productivity conditions, the orientation information of the hydraulic fracturing perforation is valid;

[0165] If the productivity difference does not meet the preset productivity conditions, re-determine the orientation information of the hydraulic fracturing perforation.

[0166] An embodiment of the present invention also provides a computer device, as Figure 10 shown, is a schematic diagram of the computer device in the embodiment of the present invention. The computer device 1000 includes a memory 1010, a processor 1020, and a computer program 1030 stored on the memory 1010 and executable on the processor 1020. When the processor 1020 executes the computer program 1030, it implements the above method for determining the orientation information of the hydraulic fracturing perforation.

[0167] An embodiment of the present invention also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the above method for determining the orientation information of the hydraulic fracturing perforation.

[0168] An embodiment of the present invention also provides a computer program product, which includes a computer program. When the computer program is executed by a processor, it implements the above method for determining the orientation information of the hydraulic fracturing perforation.

[0169] In the embodiments of the present invention, a plurality of core samples of a specified shale reservoir are obtained; acoustic emission tests are performed on the plurality of core samples to determine the azimuth information and magnitude of the maximum horizontal principal stress, and the azimuth information and magnitude of the minimum horizontal principal stress of the specified shale reservoir; paleomagnetic tests are performed on the plurality of core samples to determine the azimuth information of the natural fractures of the specified shale reservoir; a true three-dimensional hydraulic fracturing model is established by using the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of the natural fractures; the true three-dimensional hydraulic fracturing model is used to perform hydraulic fracturing on a pre-obtained hydraulic fracturing specimen to obtain hydraulic fractures, and the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approaching angle are determined; the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approaching angle are analyzed according to the azimuth information and magnitude of the maximum horizontal principal stress, the magnitude of the minimum horizontal principal stress, and the azimuth information of the natural fractures, and the hydraulic fracturing perforation azimuth information is determined according to the analysis results. In this way, through acoustic emission tests and paleomagnetic tests, the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of the natural fractures of the shale reservoir are determined. Then, after simulating hydraulic fracturing on the hydraulic fracturing specimen by using the true three-dimensional hydraulic fracturing model, the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of the natural fractures of the shale reservoir are used to analyze the hydraulic fracturing data, guide the determination of the hydraulic fracturing perforation azimuth information, improve the accuracy of the determined perforation parameters, make the reservoir perforation positioning more efficient, and thus ensure the success rate of hydraulic fracturing and improve the oilfield development effect.

[0170] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented 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.

[0171] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, and the combination of processes and / or blocks in the flowchart and / or block diagram, can be realized by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate for realizing in the process Figure 1 a process or multiple processes and / or blocks Figure 1a device for the functions specified in one or more boxes.

[0172] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory produce a manufactured article including an instruction device that implements the functions specified in one Figure 1 process or multiple processes and / or boxes Figure 1 a box or multiple boxes.

[0173] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to produce a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one Figure 1 process or multiple processes and / or boxes Figure 1 a box or multiple boxes.

[0174] In the specific embodiments described above, the objectives, technical solutions, and beneficial effects of the present invention have been further described in detail. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for determining the azimuth information of hydraulic fracturing perforation, characterized in that Comprising: Obtaining a plurality of core samples of a specified shale reservoir; Conducting acoustic emission tests on the plurality of core samples to determine the azimuth information and magnitude of the maximum horizontal principal stress, and the azimuth information and magnitude of the minimum horizontal principal stress of the specified shale reservoir; Conducting paleomagnetic tests on the plurality of core samples to determine the azimuth information of the natural fractures in the specified shale reservoir; Establishing a true three-dimensional hydraulic fracturing model by using the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of the natural fractures; Conducting hydraulic fracturing on a pre-obtained hydraulic fracturing specimen by using the true three-dimensional hydraulic fracturing model to obtain hydraulic fractures, and determining the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approaching angle; Analyzing the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approaching angle according to the azimuth information and magnitude of the maximum horizontal principal stress, the magnitude of the minimum horizontal principal stress, and the azimuth information of the natural fractures, and determining the hydraulic fracturing perforation azimuth information according to the analysis results.

2. The method according to claim 1, characterized in that, Establishing a true three-dimensional hydraulic fracturing model by using the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of the natural fractures, including: Taking the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of the natural fractures as the true triaxial loading mode information of the true three-dimensional hydraulic fracturing model.

3. The method according to claim 1, wherein The azimuth information is an azimuth angle, and the azimuth angle is used to represent the direction and position.

4. The method according to claim 3, characterized in that, Analyzing the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approaching angle according to the azimuth information and magnitude of the maximum horizontal principal stress, the magnitude of the minimum horizontal principal stress, and the azimuth information of the natural fractures, and determining the hydraulic fracturing perforation azimuth information according to the analysis results, including: When any one of the following conditions is satisfied, determining that the azimuth information of the hydraulic fracturing perforation is: the direction of the azimuth angle is the same as the direction of the natural fracture, and the position is passing through the natural fracture: The direction of the maximum horizontal principal stress and the direction of the hydraulic fracture are perpendicular, and the approaching angle is within a first preset range; The direction of the maximum horizontal principal stress and the direction of the hydraulic fracture are the same, and the approaching angle is within a second preset range; The direction of the hydraulic fracture and the direction of the natural fracture are perpendicular, and the ratio of the magnitude of the minimum horizontal principal stress to the magnitude of the maximum horizontal principal stress is greater than a preset magnitude ratio.

5. The method according to claim 3, characterized in that Analyzing the azimuth information of the hydraulic fractures, the horizontal pressure difference of the hydraulic fracturing, and the approaching angle according to the azimuth information and magnitude of the maximum horizontal principal stress, the magnitude of the minimum horizontal principal stress, and the azimuth information of the natural fractures, and determining the hydraulic fracturing perforation azimuth information according to the analysis results, including: When the horizontal pressure difference is a first preset threshold and the approaching angle is a second preset threshold, or when the horizontal pressure difference is less than a third preset threshold and the approaching angle is less than a fourth preset threshold, determining that the azimuth information of the hydraulic fracturing perforation does not intersect with the natural fracture according to the azimuth information of the natural fracture.

6. The method according to claim 1, characterized in that, Based on the azimuth information and magnitude of the maximum horizontal principal stress, the magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures, analyze the azimuth information of hydraulic fractures, the horizontal pressure difference of hydraulic fracturing, and the approaching angle. After determining the azimuth information of hydraulic fracturing perforation according to the analysis results, it further includes: Using numerical simulation methods, calculate the productivity data of the azimuth information of hydraulic fracturing perforation; If the productivity data meets the preset productivity conditions, the azimuth information of hydraulic fracturing perforation is valid; If the productivity data does not meet the preset productivity conditions, re-determine the azimuth information of hydraulic fracturing perforation.

7. A device for determining the azimuth information of hydraulic fracturing perforation, characterized in that It includes: A core acquisition module for acquiring multiple core samples of a specified shale reservoir; An acoustic emission test module for conducting acoustic emission tests on multiple core samples to determine the azimuth information and magnitude of the maximum horizontal principal stress and the azimuth information and magnitude of the minimum horizontal principal stress of the specified shale reservoir; A paleomagnetic test module for conducting paleomagnetic tests on multiple core samples to determine the azimuth information of natural fractures in the specified shale reservoir; A model construction module for establishing a true three-dimensional hydraulic fracturing model using the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures; A fracturing data processing module for using the true three-dimensional hydraulic fracturing model to perform hydraulic fracturing on pre-acquired hydraulic fracturing specimens to obtain hydraulic fractures, and determining the azimuth information of the hydraulic fractures, the horizontal pressure difference of hydraulic fracturing, and the approaching angle; A perforation azimuth determination module for analyzing the azimuth information of the hydraulic fractures, the horizontal pressure difference of hydraulic fracturing, and the approaching angle based on the azimuth information and magnitude of the maximum horizontal principal stress, the magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures, and determining the azimuth information of hydraulic fracturing perforation according to the analysis results.

8. The device according to claim 7, characterized in that, The model construction module is specifically used for: Taking the azimuth information and magnitude of the maximum horizontal principal stress, the azimuth information and magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures as the true triaxial loading mode information of the true three-dimensional hydraulic fracturing model.

9. The device according to claim 7, characterized in that, The azimuth information is an azimuth angle, and the azimuth angle is used to represent direction and position.

10. The device according to claim 9, characterized in that, The perforation azimuth determination module is specifically used for: When any of the following conditions is met, determine that the azimuth information of hydraulic fracturing perforation is: the direction of the azimuth angle is the same as the direction of the natural fracture, and the position is passing through the natural fracture: The direction of the maximum horizontal principal stress and the direction of the hydraulic fracture are perpendicular, and the approaching angle is within the first preset range; The direction of the maximum horizontal principal stress and the direction of the hydraulic fracture are the same, and the approaching angle is within the second preset range; The direction of the hydraulic fracture and the direction of the natural fracture are perpendicular, and the ratio of the magnitude of the minimum horizontal principal stress to the magnitude of the maximum horizontal principal stress is greater than the preset magnitude ratio.

11. The device according to claim 9, characterized in that The perforation azimuth determination module is also used for: When the horizontal pressure difference is the first preset threshold and the approaching angle is the second preset threshold, or when the horizontal pressure difference is less than the third preset threshold and the approaching angle is less than the fourth preset threshold, determine that the azimuth information of hydraulic fracturing perforation does not intersect with the natural fracture according to the azimuth information of the natural fracture.

12. The device according to claim 7, characterized in that, It further includes a perforation azimuth verification module, which is used after the perforation azimuth determination module analyzes the azimuth information and magnitude of the maximum horizontal principal stress, the magnitude of the minimum horizontal principal stress, and the azimuth information of natural fractures to determine the azimuth information of hydraulic fractures, the horizontal pressure difference of hydraulic fracturing, and the approach angle, and determines the perforation azimuth information of hydraulic fracturing according to the analysis results: Using numerical simulation methods, calculate the production data of the perforation azimuth information of hydraulic fracturing; If the production data meets the preset production conditions, the perforation azimuth information of hydraulic fracturing is valid; If the production data does not meet the preset production conditions, re-determine the perforation azimuth information of hydraulic fracturing.

13. A computer device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method according to any one of claims 1 to 6.

14. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the method according to any one of claims 1 to 6.

15. A computer program product, characterized in that, The computer program product includes a computer program, and when the computer program is executed by a processor, it implements the method according to any one of claims 1 to 6.

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