Biaxial anisotropic stratum equivalent model construction and logging response determination method

Abstract

The invention discloses a biaxial anisotropic stratum equivalent model construction and logging response determination method. The method comprises the steps that a one-dimensional horizontal layered biaxial anisotropic formation model is constructed, the one-dimensional horizontal layered biaxial anisotropic formation model comprises a plurality of first formations, values of a plurality of equivalent parameters of each first formation are determined according to values of resistivity of the first formations in the x direction, the y direction and the z direction, and the values of the equivalent parameters of the first formations are determined according to the values of resistivity of the first formations in the x direction, the y direction and the z direction; obtaining an equivalent model of each first stratum, obtaining resistivity values and degrees of inclination angles of each stratum of the target biaxial anisotropic stratum in the x direction, the y direction and the z direction, obtaining an equivalent model of the target stratum by using a construction method of the equivalent model of the biaxial anisotropic stratum, and calculating an induction logging response of the equivalent model, and taking a calculation result as an induction logging response of the target biaxial anisotropic stratum. And the biaxial anisotropic formation induction logging response can be quickly and efficiently determined.

Description

Technical Field

[0001] The invention relates to the technical field of electrical logging in petroleum exploration and development, and in particular to a method for constructing a biaxial anisotropic formation equivalent model and determining a logging response. Background Art

[0002] In recent years, unconventional and complex oil and gas reservoirs have become the key to increasing oil and gas reserves and production. Such reservoirs usually have significant resistivity anisotropy. Existing technologies widely use induction logging instruments to detect formation electrical information, but due to the serious influence of inclination, layer thickness and formation anisotropy, the qualitative interpretation and quantitative evaluation of induction logging data are difficult. Based on this, establishing a fast and accurate induction logging forward modeling to meet the needs of fast and real-time processing of such data is the key to solving the problem.

[0003] In actual exploration and development, shale reservoirs have obvious biaxial anisotropy characteristics of resistivity. The traditional pseudo-analytical method is used to calculate the logging response, which relies on double Fourier transform and spectral field recursion algorithm. However, the calculation speed is slow and cannot meet the needs of fast and real-time data processing. Therefore, there is an urgent need for a method to quickly, efficiently and accurately calculate the biaxial anisotropic formation induction logging response. Summary of the invention

[0004] In view of the above problems, the present invention is proposed to provide a method and device for calculating biaxial anisotropic formation induction logging response that overcomes the above problems or at least partially solves the above problems.

[0005] In a first aspect, an embodiment of the present invention provides a method for constructing a biaxial anisotropic formation equivalent model, comprising:

[0006] Constructing a one-dimensional horizontal layered biaxial anisotropic formation model, wherein the one-dimensional horizontal layered biaxial anisotropic formation model includes a plurality of first formations, wherein the parameters of the first formations include resistivity in the x-direction, the y-direction and the z-direction, and the first formations have resistivity anisotropy characteristics; the x-direction and the y-direction are two directions perpendicular to each other on a horizontal plane, and the z-direction is a direction perpendicular to the horizontal plane;

[0007] Determine the values ​​of multiple equivalent parameters of each first stratum according to the resistivity values ​​of each first stratum in the x-direction, the y-direction and the z-direction, and obtain an equivalent model of each first stratum;

[0008] The set of equivalent models of the first formations is taken as a biaxial anisotropic formation equivalent model.

[0009] In one embodiment, the equivalent parameters include vertical resistivity and horizontal resistivity;

[0010] The method of determining the values ​​of several equivalent parameters of each first stratum according to the resistivity values ​​of each first stratum in the x-direction, the y-direction and the z-direction to obtain the equivalent model of each first stratum includes:

[0011] For each first stratum, taking the resistivity value of the first stratum in the z direction as the value of the vertical resistivity of the first stratum;

[0012] Determining a value of horizontal resistivity of the first formation according to resistivity values ​​of the first formation in the x-direction and the y-direction;

[0013] An equivalent model of the first formation is obtained according to the value of the vertical resistivity and the value of the horizontal resistivity of the first formation.

[0014] In one embodiment, determining the horizontal resistivity of the first formation according to the resistivity of the first formation in the x-direction and the y-direction includes:

[0015] Calculating the square root of the product of the resistivity values ​​of the first formation in the x-direction and the y-direction to obtain an initial resistivity value;

[0016] In the case where the first formation has uniaxial anisotropy characteristics, taking the initial resistivity value as the value of the horizontal resistivity of the first formation;

[0017] In the case that the first formation has a biaxial anisotropic characteristic, the biaxial anisotropic response of the first formation is determined, and the horizontal resistivity value of the first formation is determined based on the biaxial anisotropic response and the initial resistivity value.

[0018] In one embodiment, determining the horizontal resistivity of the first formation according to the biaxial anisotropic response and the initial resistivity comprises:

[0019] According to the initial resistivity value, the uniaxial anisotropic response of the first formation is solved by using a uniform medium analytical formula;

[0020] Calculate the fitting difference between the biaxial anisotropic response and the uniaxial anisotropic response, and determine whether the fitting difference is less than a preset fitting difference threshold; if so, use the initial resistivity value as the value of the horizontal resistivity of the first formation; if not, determine the value of the horizontal resistivity of the first formation based on the biaxial anisotropic response, the uniaxial anisotropic response and the initial resistivity value of the first formation.

[0021] In one embodiment, determining the value of the horizontal resistivity of the first formation according to the biaxial anisotropic response, the uniaxial anisotropic response and the initial resistivity value of the first formation comprises:

[0022] updating the initial resistivity value by using an inversion algorithm according to the biaxial anisotropic response, the uniaxial anisotropic response and the initial resistivity value of the first formation;

[0023] According to the updated initial resistivity value, the uniaxial anisotropic response is updated using a uniform medium analytical formula;

[0024] According to the biaxial anisotropic response of the first formation, the updated uniaxial anisotropic response and the updated initial resistivity value, the initial resistivity value and the uniaxial anisotropic response are updated again by using an inversion algorithm, and the step of updating the initial resistivity value and the uniaxial anisotropic response again is repeatedly performed until the fitting difference between the updated uniaxial anisotropic response and the biaxial anisotropic response is greater than or equal to the fitting difference threshold;

[0025] The initial resistivity value updated after the iteration is terminated is used as the horizontal resistivity of the first formation.

[0026] In one embodiment, the biaxial anisotropic response of the first formation is determined by:

[0027] determining a spatial domain magnetic field in a stratigraphic coordinate system of the first stratigraphic layer;

[0028] Converting the spatial domain magnetic field in the formation coordinate system to the instrument coordinate system to obtain the spatial domain magnetic field in the instrument coordinate system;

[0029] The product of the spatial domain magnetic field in the instrument coordinate system and the pre-acquired instrument coefficient is taken as the biaxial anisotropic response of the first formation.

[0030] In one embodiment, determining the spatial domain magnetic field of the first formation in a formation coordinate system includes:

[0031] Maxwell equations are used to perform Fourier transform along the x-direction, the y-direction and the z-direction. After the Fourier transform is completed, the spectral domain magnetic field of the first formation is solved to obtain an analytical expression of the spectral domain magnetic field;

[0032] An inverse Fourier transform is performed on the spectral domain magnetic field analytical expression to obtain the spatial domain magnetic field in the formation coordinate system of the first formation.

[0033] In one embodiment, the parameter of the first formation further includes an inclination angle, and the inclination angle is a relative inclination angle between the tool axis and the first formation;

[0034] The performing inverse Fourier transform on the spectral domain magnetic field analytical expression to obtain the spatial domain magnetic field in the formation coordinate system of the first formation includes:

[0035] Perform inverse Fourier transform on the spectral domain magnetic field analytical expression to obtain the spatial domain magnetic field expression. Use the symmetry and antisymmetry laws of the spectral domain magnetic field in the four integral quadrants and the residue theorem to simplify the spatial domain magnetic field expression.

[0036] When the degree of the inclination angle is less than a preset inclination angle threshold, a double Gauss-Legendre integral is used to solve the simplified spatial domain magnetic field expression to determine the spatial domain magnetic field in the formation coordinate system;

[0037] When the degree of the inclination angle is greater than or equal to a preset inclination angle threshold, double sine-cosine filter integration is used to solve the simplified spatial domain magnetic field expression to determine the spatial domain magnetic field in the formation coordinate system.

[0038] In one embodiment, the one-dimensional horizontal layered biaxial anisotropic formation model further includes a plurality of second formations, and the second formations have isotropic characteristics.

[0039] In a second aspect, an embodiment of the present invention provides a method for determining a biaxial anisotropic formation response, comprising:

[0040] Obtaining the resistivity values ​​and dip angles of each stratum in the x-direction, y-direction and z-direction of the target biaxial anisotropic stratum, and constructing a biaxial anisotropic stratum equivalent model corresponding to the target biaxial anisotropic stratum according to the resistivity values ​​and dip angles of each stratum in the x-direction, y-direction and z-direction, wherein the biaxial anisotropic stratum equivalent model is obtained by the aforementioned biaxial anisotropic stratum equivalent model construction method;

[0041] The response of the biaxial anisotropic formation equivalent model corresponding to the target formation is calculated to obtain the response of the target biaxial anisotropic formation.

[0042] In a third aspect, an embodiment of the present invention provides a device for constructing a biaxial anisotropic formation equivalent model, comprising:

[0043] A first construction module is used to construct a one-dimensional horizontal layered biaxial anisotropic formation model, wherein the one-dimensional horizontal layered biaxial anisotropic formation model includes a plurality of first formations, the parameters of the first formations include resistivity in the x-direction, the y-direction and the z-direction, and the first formations have resistivity anisotropy characteristics; the x-direction and the y-direction are two directions perpendicular to each other on a horizontal plane, and the z-direction is a direction perpendicular to the horizontal plane;

[0044] The first determination module is used to determine the values ​​of multiple equivalent parameters of each first stratum according to the resistivity values ​​of each first stratum in the x-direction, the y-direction and the z-direction, respectively, to obtain an equivalent model of each first stratum,

[0045] The second determination module is used to use the set of equivalent models of the first formations as a biaxial anisotropic formation equivalent model.

[0046] In a fourth aspect, an embodiment of the present invention provides a device for determining a biaxial anisotropic formation response, comprising:

[0047] The second construction module is used to obtain the resistivity values ​​and the degree of inclination of each stratum in the x-direction, y-direction and z-direction of the target biaxial anisotropic stratum, and to construct a biaxial anisotropic stratum equivalent model corresponding to the target biaxial anisotropic stratum according to the resistivity values ​​and the degree of inclination of each stratum in the x-direction, y-direction and z-direction. The biaxial anisotropic stratum equivalent model is obtained by the aforementioned biaxial anisotropic stratum equivalent model construction method.

[0048] The calculation module is used to calculate the response of the biaxial anisotropic formation equivalent model corresponding to the target formation to obtain the response of the target biaxial anisotropic formation.

[0049] In a fifth aspect, an embodiment of the present invention provides a computer storage medium, in which computer executable instructions are stored. When the computer executable instructions are executed by a processor, the method for constructing an equivalent model of a biaxial anisotropic formation as described above or the method for determining a biaxial anisotropic formation response as described above is implemented.

[0050] In a sixth aspect, an embodiment of the present invention provides a terminal device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, it implements the aforementioned method for constructing a biaxial anisotropic formation equivalent model or the aforementioned method for determining a biaxial anisotropic formation response.

[0051] In the seventh aspect, an embodiment of the present invention provides a computer program product, which includes a computer program. When the computer program is executed by a processor, it implements the method for constructing a biaxial anisotropic formation equivalent model as mentioned above or the method for determining a biaxial anisotropic formation response as mentioned above.

[0052] The beneficial effects of the above technical solution provided by the embodiment of the present invention include at least:

[0053] The method for constructing a biaxial anisotropic formation equivalent model provided by an embodiment of the present invention constructs a one-dimensional horizontal layered biaxial anisotropic formation model including a plurality of first formations, each of which has anisotropic resistivity characteristics, and determines the values ​​of multiple equivalent parameters of each formation according to the resistivity values ​​of each first formation in the x-direction, the y-direction and the z-direction, and accordingly obtains an equivalent model of each formation, and uses the set of equivalent models of each first formation as an equivalent model of the biaxial anisotropic formation; utilizes the multi-solution of the induction logging response of the uniform anisotropic formation to determine the equivalent model of each formation, and converts the problem of solving the logging response of the biaxial anisotropic formation model into the problem of solving the logging response of the equivalent model of the biaxial anisotropic formation, thereby simplifying the calculation model.

[0054] In addition, for each first formation, the resistivity value of the first formation in the z direction is used as the value of the vertical resistivity of the first formation; the horizontal resistivity value of the first formation is determined according to the resistivity values ​​of the first formation in the x direction and the y direction, and then the equivalent model of the first formation is obtained according to the vertical resistivity and horizontal resistivity values ​​of the first formation; and because the x direction and the y direction are two directions perpendicular to each other on the horizontal plane, and the z direction is a direction perpendicular to the horizontal plane, in other words, the biaxial anisotropic formation is equivalent to the uniaxial anisotropic formation, and the advantage of the fast calculation speed of the logging response of the uniaxial anisotropic formation is utilized to overcome the bottleneck of the slow calculation speed of the original biaxial anisotropic formation logging response, and solve the problem of slow speed and large amount of calculation of the existing technology for calculating the logging response of the biaxial anisotropic formation, which lays a foundation for the qualitative evaluation and quantitative interpretation of the induction logging data of inclined wells and horizontal wells in complex reservoirs such as shale.

[0055] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0056] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0058] Figure 1 This is one of the flow charts of the method for constructing a biaxial anisotropic formation equivalent model in the first embodiment of the present invention;

[0059] Figure 2 This is one of the structural schematic diagrams of the model M in the first embodiment of the present invention;

[0060] Figure 3 Schematic diagram of the structure of an equivalent model of the model M in the first embodiment of the present invention;

[0061] Figure 4 This is the second structural diagram of the model M in the first embodiment of the present invention;

[0062] Figure 5 A flow chart of a method for determining an equivalent model of each first formation in Embodiment 1 of the present invention;

[0063] Figure 6 This is a flow chart of a method for determining a biaxial anisotropic response of a first formation in Embodiment 1 of the present invention;

[0064] Figure 7 This is a flow chart of a method for determining a spatial domain magnetic field in a formation coordinate system in Embodiment 1 of the present invention;

[0065] Figure 8 This is one of the flow charts of the method for determining the horizontal resistivity of the first formation in the first embodiment of the present invention;

[0066] Fig. 9 This is a second flow chart of the method for determining the horizontal resistivity of the first formation in the first embodiment of the present invention;

[0067] Fig.10 This is a second flow chart of the method for constructing a biaxial anisotropic formation equivalent model in the first embodiment of the present invention;

[0068] Fig.11 It is a structural schematic diagram of a biaxial anisotropic formation equivalent model in the first embodiment of the present invention;

[0069] Fig.12 The induction logging response calculated by the model M and the equivalent model when the inclination angles of the instrument are 0°, 45° and 85° in the first embodiment of the present invention;

[0070] Fig.13 Schematic diagram of the error results between the induction logging responses of the model M and the equivalent model when the instrument inclination angles are 0°, 45° and 85° in the first embodiment of the present invention;

[0071] Fig.14 This is one of the flow charts of the method for determining biaxial anisotropic formation response in the second embodiment of the present invention;

[0072] Fig.15 This is a second flow chart of a method for determining biaxial anisotropic formation response in the second embodiment of the present invention;

[0073] Fig.16 Schematic diagram of the structure of a device for constructing a biaxial anisotropic formation equivalent model in an embodiment of the present invention;

[0074] Fig.17 Schematic diagram of the structure of a device for determining biaxial anisotropic formation response in an embodiment of the present invention. DETAILED DESCRIPTION

[0075] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0076] In order to solve the problems existing in the prior art, an embodiment of the present invention provides a method for constructing a biaxial anisotropic formation equivalent model and determining a logging response.

[0077] Embodiment 1

[0078] In order to more concisely and clearly explain the method for constructing the equivalent model of the biaxial anisotropic formation, in the embodiment of the present invention, the constructed one-dimensional horizontal layered biaxial anisotropic formation model is referred to as model M, and the equivalent model of each first formation is referred to as M TI ;

[0079] The first stratum and the second stratum described in the embodiment of the present invention are both strata.

[0080] Embodiment 1 of the present invention provides a method for constructing a biaxial anisotropic formation equivalent model, the process of which is as follows: Figure 1 As shown, the following steps are included:

[0081] Step S1: constructing a one-dimensional horizontal layered biaxial anisotropic formation model, wherein the one-dimensional horizontal layered biaxial anisotropic formation model includes a plurality of first formations, wherein the parameters of the first formations include resistivity in the x-direction, the y-direction and the z-direction, and the first formations have resistivity anisotropy characteristics; the x-direction and the y-direction are two directions perpendicular to each other on a horizontal plane, and the z-direction is a direction perpendicular to the horizontal plane;

[0082] Step S2: according to the resistivity values ​​of each first stratum in the x-direction, the y-direction and the z-direction, respectively determining the values ​​of a plurality of equivalent parameters of each first stratum, and obtaining an equivalent model of each first stratum;

[0083] Step S3: taking the set of equivalent models of the first formations as a biaxial anisotropic formation equivalent model.

[0084] Determine the parameters of the one-dimensional horizontal layered biaxial anisotropic formation model, namely model M. The parameters of model M include: induction logging frequency (denoted as f), source distance (denoted as L), resistivity of each formation in the x-direction, y-direction and z-direction in model M (denoted by Rx , R y , R z The model M is constructed by using the values ​​of the parameters in the above model M. The constructed model M is referenced by Figure 2 As shown, Figure 2 In the model M, there are N strata, N-1 stratum interfaces (denoted as Z), and dip angle θ. The resistivity of the first stratum in the x-, y-, and z-directions are R x，1 , R y，1 , R z，1 The resistivity of the mth layer in the x-, y-, and z-directions are R x,m , R y,m , R z，m , and so on, the resistivity of the Nth layer in the x-direction, y-direction, and z-direction are R x,N , R y,N , R z，N .

[0085] The equivalent parameters of the biaxial anisotropic formation equivalent model include vertical resistivity (denoted as R v ) and horizontal resistivity (denoted as R h ),by Figure 2 The model M shown in FIG. 1 is subjected to steps S1 to S3 to obtain a biaxial anisotropic formation equivalent model (M TI , that is, the equivalent model of model M) as an example, the equivalent model M TI refer to Figure 3 As shown, Figure 3 The left side is model M, the right side is M TI , M TI There are N strata, N-1 stratum interfaces Z, and dip angle θ. Each stratum corresponds to each stratum in model M. TI In the figure, the vertical resistivity and horizontal resistivity of the first layer are R v，1 and R h，1 , the vertical and horizontal resistivities of the mth stratum are R v，m and R h,m , and so on, the vertical and horizontal resistivities of the Nth stratum are R v，N and R h，N .

[0086] In some optional embodiments, the one-dimensional horizontal layered biaxial anisotropic formation model in the above step S1, that is, the model M includes a plurality of first formations, the first formations have anisotropic characteristics, and also includes a plurality of second formations, the second formations have isotropic characteristics. Specifically, if the resistivity values ​​of the formations in the x-direction, y-direction, and z-direction are all the same, the formation is the second formation, and if the resistivity values ​​of the formations in the x-direction, y-direction, and z-direction are not the same, the formation is the first formation;

[0087] In the first formation, if the resistivity values ​​in the x-direction and y-direction of the first formation are equal (i.e., R x =R y ), the first stratum has uniaxial anisotropy characteristics, and accordingly, the first stratum is called a uniaxial anisotropic stratum; if the resistivity values ​​of the first stratum in the x-direction and the y-direction are not equal (i.e., R x ≠R y ), the first stratum has a biaxial anisotropic characteristic, and accordingly, the first stratum is called a biaxial anisotropic stratum;

[0088] Using a specific example of the first and second strata, refer to Figure 4 As shown, Figure 4 The dotted line in the figure represents the formation interface and the relative inclination between the tool axis and the formation. The induction logging frequency f is 20kHz, the source distance L is 0.5m, Figure 4 The model M has three layers, among which the first layer R x,1 , R y,1 With R z，1 The values ​​of the third layer are all 1Ω·m. x,3 , R y,3 With R z，3 The values ​​of are all 1Ω·m, so the first and third strata are isotropic resistivity strata, that is, the second stratum. The resistivities of the second stratum in the x-, y- and z-directions are 3Ω·m, 10Ω·m and 15Ω·m respectively, so the second stratum is anisotropic resistivity stratum, that is, the first stratum.

[0089] In some optional embodiments, for each first stratum in the model M, the anisotropic characteristics of each first stratum are analyzed, and according to the analysis results, the above step S2 is performed to determine the values ​​of multiple equivalent parameters of each first stratum according to the resistivity values ​​of each first stratum in the x-direction, y-direction and z-direction, respectively, with reference to Figure 5 As shown, this can be achieved by:

[0090] Step S51: for each first stratum, taking the resistivity value of the first stratum in the z direction as the vertical resistivity value of the first stratum;

[0091] Step S52: determining the horizontal resistivity value of the first stratum according to the resistivity values ​​of the first stratum in the x-direction and the y-direction;

[0092] Step S53: Obtaining an equivalent model of the first formation according to the vertical resistivity value and the horizontal resistivity value of the first formation.

[0093] In some optional embodiments, the horizontal resistivity value of the first formation is determined in the above step S52 in two cases: one is the case where the first formation has a uniaxial anisotropy characteristic, and the other is the case where the first formation has a biaxial anisotropy characteristic. For the above two cases, the horizontal resistivity value of the first formation can be determined in the following manner:

[0094] Case 1: The first stratum has uniaxial anisotropy characteristics:

[0095] (1) Calculate the square root of the product of the resistivity values ​​of the first formation in the x direction and the y direction to obtain an initial resistivity value;

[0096] (2) When the first stratum has uniaxial anisotropy characteristics, the initial resistivity value is used as the horizontal resistivity value of the first stratum.

[0097] For example, if the R of the first formation x =1Ω·m, R y =1Ω·m, R z =5Ω·m, that is, the resistivity in the x-direction, y-direction, and z-direction is not the same, and the resistivity in the x-direction is equal to that in the y-direction. It is judged that the first formation has uniaxial anisotropy characteristics, and the vertical resistivity R of the first formation is v =R z =5Ω·m, the horizontal resistivity of the first formation Continuing to execute step S53, a uniaxial anisotropic formation model of the first formation (denoted as M) is constructed according to the determined values ​​of the vertical resistivity and the horizontal resistivity. TI , i (i indicates that the first stratum is the i-th stratum of model M)).

[0098] Case 2: The first stratum has biaxial anisotropy characteristics:

[0099] (1) Calculate the square root of the product of the resistivity values ​​of the first formation in the x direction and the y direction to obtain an initial resistivity value;

[0100] (2) When the first formation has a biaxial anisotropic characteristic, the biaxial anisotropic response of the first formation is determined, and the horizontal resistivity value of the first formation is determined based on the biaxial anisotropic response and the initial resistivity value.

[0101] In some optional embodiments, if the first formation has a biaxial anisotropic characteristic, the thickness effect of the first formation is ignored, and a uniform biaxial anisotropic formation model (denoted as M BA , i (i indicates that the first stratum is the i-th stratum in model M)), model M BA,i The parameters are the resistivity in the x direction, the resistivity in the y direction, the resistivity in the z direction and the dip angle of the ith formation in the model M. Figure 4 Take the model M shown as an example, Figure 4 The model M shown in the figure has a total of three strata, among which the first and third layers have isotropic characteristics (isotropic resistivity characteristics), and the second layer has anisotropic characteristics. Therefore, the thickness of the second layer is regarded as infinite, that is, the thickness effect of the second layer is ignored, and a uniform biaxial anisotropic stratum model is established for the second layer, which is recorded as M BA,2 , and M BA，2 R x，2 =3Ω·m, R y,2 =10Ω·m and R z，2 =15Ω·m, based on this, the biaxial anisotropic response of the first formation can be determined in the following way:

[0102] Step S61: determining the spatial domain magnetic field of the first stratum in the stratum coordinate system;

[0103] Step S62: converting the space domain magnetic field in the formation coordinate system into the instrument coordinate system to obtain the space domain magnetic field in the instrument coordinate system;

[0104] Step S63: The product of the spatial domain magnetic field in the instrument coordinate system and the pre-acquired instrument coefficient is taken as the biaxial anisotropic response of the first formation.

[0105] In some optional embodiments, the above step S61 may determine the spatial domain magnetic field in the formation coordinate system of the first formation in the following manner:

[0106] (1) Perform Fourier transform on Maxwell's equations along the x, y and z directions. After the Fourier transform is completed, the spectral domain magnetic field of the first formation is solved to obtain an analytical expression of the spectral domain magnetic field;

[0107] The Maxwell equations are triple Fourier transformed along the x, y and z directions. After the Fourier transform is completed, the spectral domain magnetic field of the first formation is solved using the following formula:

[0108]

[0109] In the above formula (1), is the spectral domain magnetic field, and H(x, y, z) is the spatial domain magnetic field.

[0110] (2) Perform inverse Fourier transform on the spectral domain magnetic field analytical expression to obtain the spatial domain magnetic field in the stratigraphic coordinate system of the first stratum.

[0111] Because the parameters of the first formation also include the inclination angle, which is the relative inclination angle between the tool axis and the first formation, specifically, according to the degree of the inclination angle, reference Figure 7 As shown, the following method is used to perform inverse Fourier transform on the spectral domain magnetic field analytical expression to determine the spatial domain magnetic field in the formation coordinate system:

[0112] Step S71: Perform inverse Fourier transform on the spectral domain magnetic field analytical expression to obtain the spatial domain magnetic field expression, and simplify the spatial domain magnetic field expression by using the symmetry and antisymmetry laws of the spectral domain magnetic field in four integral quadrants and the residue theorem;

[0113] The expression of the magnetic field in the space domain is as follows:

[0114]

[0115] The parameters in formula (2) have been described above and will not be described in detail in the embodiment of the present invention.

[0116] First, the residue theorem is used to avoid infinite integration of , and the triple integral is analytically simplified to two dimensions. Then, the double infinite integral is further simplified to a double semi-infinite integral by using the symmetry and antisymmetry of the spectral domain magnetic field in the four integral quadrants, and the simplified spatial domain magnetic field expression is obtained:

[0117]

[0118] The parameters in formula (3) have been described above and will not be described in detail in the embodiment of the present invention.

[0119] Step S72: when the inclination angle is less than a preset inclination angle threshold, a double Gauss-Legendre integral is used to solve a simplified spatial domain magnetic field expression to determine the spatial domain magnetic field in the formation coordinate system;

[0120] Step S73: When the inclination angle is greater than or equal to the preset inclination angle threshold, a double sine-cosine filter integral is used to solve the simplified spatial domain magnetic field expression to determine the spatial domain magnetic field in the formation coordinate system.

[0121] The preset inclination angle threshold may be 45 degrees, which is not limited in the embodiment of the present invention. The spatial domain magnetic field in the stratigraphic coordinate system of the first stratigraphic layer is as follows:

[0122] In some optional embodiments, in the above step S62, the spatial domain magnetic field in the formation coordinate system is converted to the instrument coordinate system using a rotation matrix to obtain the spatial domain magnetic field in the instrument coordinate system.

[0123] After the biaxial anisotropic response of the first formation is determined, refer to Figure 8 As shown, the horizontal resistivity of the first formation can be determined by:

[0124] Step S81: according to the initial resistivity, using the uniform medium analytical formula, solve the uniaxial anisotropic response of the first formation;

[0125] The analytical formula for uniform media is a prior art, and the embodiment of the present invention does not elaborate on the process of solving the uniaxial anisotropic response of the first formation.

[0126] Step S82: Calculate the fitting difference between the biaxial anisotropic response and the uniaxial anisotropic response, and determine whether the fitting difference is less than a preset fitting difference threshold. If so, use the initial resistivity value as the value of the horizontal resistivity of the first formation; if not, determine the value of the horizontal resistivity of the first formation based on the biaxial anisotropic response, the uniaxial anisotropic response and the initial resistivity value of the first formation.

[0127] Optionally, the preset fit error threshold can be set to 10 -3 , can also be set to other values, which are not limited in the embodiment of the present invention. The uniaxial anisotropic response of the formation is calculated through the initial resistivity value of the formation. If the fitting difference between the biaxial anisotropic response and the uniaxial anisotropic response of the formation is less than the fitting difference threshold, that is, the fitting difference between the biaxial anisotropic response and the uniaxial anisotropic response is small enough, in other words, the biaxial anisotropic response and the uniaxial anisotropic response are close enough, in this case, the initial resistivity value is used as the value of the horizontal resistivity, and the equivalent model of the formation is obtained through the value of the horizontal resistivity and the value of the vertical resistivity of the formation.

[0128] In some optional embodiments, in the above step S82, if the fitting difference between the uniaxial anisotropic response of the formation obtained by calculating the initial resistivity of the formation and the biaxial anisotropic response of the formation is greater than or equal to the fitting difference threshold, then the horizontal resistivity value of the first formation is determined according to the biaxial anisotropic response, the uniaxial anisotropic response and the initial resistivity value of the first formation, and the reference Fig. 9 As shown, this can be achieved by:

[0129] Step S91: updating the initial resistivity value by using an inversion algorithm according to the biaxial anisotropic response, the uniaxial anisotropic response and the initial resistivity value of the first formation;

[0130] Step S92: updating the uniaxial anisotropic response using a uniform medium analytical formula according to the updated initial resistivity value;

[0131] Step S93: according to the biaxial anisotropic response of the first formation, the updated uniaxial anisotropic response and the updated initial resistivity value, the initial resistivity value and the uniaxial anisotropic response are updated again by using an inversion algorithm, and the step of updating the initial resistivity value and the uniaxial anisotropic response again is repeated until the fitting difference between the updated uniaxial anisotropic response and the biaxial anisotropic response is greater than or equal to a fitting difference threshold;

[0132] Step S94: The initial resistivity value updated after the iteration is terminated is used as the horizontal resistivity value of the first formation.

[0133] The initial resistivity is iteratively updated using the following formula:

[0134]

[0135] In the above formula (4), J is the Jacobian matrix, J T is the transpose of the Jacobian matrix, i represents the i-th layer of the model M, k represents the k-th iteration, and d BA，i Biaxial anisotropic response of the ith layer in model M, d TI，i，k-1 is the uniaxial anisotropic response of the ith formation calculated after the k-1th iteration, R h，i，k-1 represents the horizontal resistivity of the ith formation after the k-1th iteration, R ni，k represents the horizontal resistivity of the i-th formation after the k-th iteration;

[0136] After each iteration, the initial resistivity value is updated, and the uniaxial anisotropic response is updated using the homogeneous medium analytical formula, and the fitting difference between the updated uniaxial anisotropic response and the biaxial anisotropic response is calculated;

[0137] The condition for terminating the above iteration is: if the fitting difference between the updated uniaxial anisotropic response and the biaxial anisotropic response is less than the fitting difference threshold, the initial resistivity value updated in the last iteration is used as the horizontal resistivity value of the first formation. Through the iterative process, the error between the uniaxial anisotropic response and the biaxial anisotropic response of the first formation is controlled within a small range, so that the uniaxial anisotropic response of the calculated equivalent model is extremely close to the biaxial anisotropic response of the actual formation model, thereby improving the accuracy of the equivalent model and ensuring the accuracy of the results.

[0138] In order to more clearly illustrate the process of constructing an equivalent model for a stratum with biaxial anisotropy, refer to Fig.10 As shown, Fig.10In , i represents the ith formation in the model M. When k is 1, the resistivity value of the ith formation in the z direction is taken as the vertical resistivity value of the formation, and the square root of the product of the resistivity values ​​of the formation in the x and y directions (i.e., the initial resistivity value of the formation) is taken as the horizontal resistivity value of the formation. The uniaxial anisotropic response of the formation is calculated. According to the value of , the fitting difference between the uniaxial anisotropic response and the biaxial anisotropic response of the formation is calculated to determine whether the fitting difference is less than . If so, the initial resistivity value of the formation is taken as the horizontal resistivity value of the formation. If not, the Jacobian matrix is ​​used to iteratively update the uniaxial anisotropic response and the initial resistivity value of the formation using formula (4) until the fitting difference between the updated uniaxial anisotropic response and the biaxial anisotropic response is less than . Then the initial resistivity value obtained by the last update is taken as the horizontal resistivity value of the formation.

[0139] In some optional embodiments, in the above step S3, the set of equivalent models of the first formations is used as a biaxial anisotropic formation equivalent model (denoted as M TI ), the second stratum in model M is not processed. A specific example is used to illustrate. Figure 4 Taking the data shown as an example, Figure 4 There are three strata in total, of which the first and third strata are isotropic strata, and the second stratum is anisotropic strata. After processing from step S1 to step S3, the equivalent model reference Fig.11 As shown, Fig.11 In the process, an equivalent model is constructed for the second stratum, and the first and third strata are not processed, and finally an equivalent model of a biaxial anisotropic stratum is obtained.

[0140] In order to verify the relative inclination between the tool axis and the formation at any degree, the model M TI Both are applicable. Compared with the same inclination angle, model M TI The induction logging response of model M, for example, the calculation of the inclination angles of v degrees, 45 degrees and 85 degrees respectively TI The induction logging response of model M at inclination angles of 0, 45 and 85 degrees, respectively. Fig.12 As shown, Fig.12 The figure on the left shows the logging response of model M when the inclination angles are 0, 45, and 85 degrees. Fig.12 The figure on the right shows the model M when the inclination angles are 0 degrees, 45 degrees, and 85 degrees. TI The logging response is based on Fig.12 The logging response results of the two models are compared. Under the same inclination degree, the model M TI The error of the induction logging response with model M, ref. Fig.13 As shown, according to Fig.13 It can be seen that after the processing of steps S1 to S3, model M can be approximately equivalent to model M TI (Uniaxial anisotropic model), the response errors calculated before and after equivalence are all within 3%, which meets the needs of practical engineering applications.

[0141] Embodiment 2

[0142] Embodiment 2 of the present invention provides a method for determining biaxial anisotropic formation response, the process of which is as follows: Fig.14 As shown, the following steps are included:

[0143] Step S131: Obtain the resistivity values ​​and dip angles of each stratum in the target biaxial anisotropic stratum in the x-direction, y-direction and z-direction, and construct a biaxial anisotropic stratum equivalent model corresponding to the target biaxial anisotropic stratum according to the resistivity values ​​and dip angles of each stratum in the x-direction, y-direction and z-direction. The biaxial anisotropic stratum equivalent model is obtained by the aforementioned biaxial anisotropic stratum equivalent model construction method.

[0144] Step S132: Calculate the response of the biaxial anisotropic formation equivalent model corresponding to the target formation to obtain the response of the target biaxial anisotropic formation.

[0145] Specifically, the pseudo-analytical forward algorithm of induction logging in one-dimensional horizontal layered uniaxial anisotropic media is called, and combined with the Sommerfeld integration method, the induction logging response of the equivalent model of the biaxial anisotropic formation is quickly calculated as the response of the target biaxial anisotropic formation.

[0146] In order to more clearly illustrate the process of determining the biaxial anisotropic formation response, refer to Fig.15 As shown, Fig.15 The left side of the middle part implements step S131, Fig.15 The right side implements step S132.

[0147] Based on the same inventive concept, the embodiment of the present invention also provides a device for constructing a biaxial anisotropic formation equivalent model, the structure of which is as follows: Fig.16 As shown, including:

[0148] The first construction module 141 is used to construct a one-dimensional horizontal layered biaxial anisotropic formation model, which includes a plurality of first formations, the parameters of which include resistivity in the x-direction, the y-direction and the z-direction, and the first formation has resistivity anisotropy characteristics; the x-direction and the y-direction are two directions perpendicular to each other on the horizontal plane, and the z-direction is a direction perpendicular to the horizontal plane;

[0149] The first determination module 142 is used to determine the values ​​of multiple equivalent parameters of each first formation according to the resistivity values ​​of each first formation in the x-direction, y-direction and z-direction, and obtain an equivalent model of each first formation.

[0150] The second determination module 143 is used to use the set of equivalent models of the first formations as a biaxial anisotropic formation equivalent model.

[0151] Regarding the device for constructing the biaxial anisotropic formation equivalent model in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0152] Based on the same inventive concept, an embodiment of the present invention further provides a device for determining a biaxial anisotropic formation response, the structure of which is as follows: Fig.17 As shown, including:

[0153] The second construction module 151 is used to obtain the resistivity values ​​and the dip angles of each layer of the target biaxial anisotropic formation in the x-direction, y-direction and z-direction, and to construct a biaxial anisotropic formation equivalent model corresponding to the target biaxial anisotropic formation according to the resistivity values ​​and the dip angles of each layer in the x-direction, y-direction and z-direction, wherein the biaxial anisotropic formation equivalent model is obtained by the aforementioned biaxial anisotropic formation equivalent model construction method;

[0154] The calculation module 152 is used to calculate the response of the biaxial anisotropic formation equivalent model corresponding to the target formation, and obtain the response of the target biaxial anisotropic formation.

[0155] Regarding the device for determining the biaxial anisotropic formation response in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0156] Unless otherwise specifically stated, terms such as processing, computing, calculating, determining, displaying, etc. may refer to the actions and / or processes of one or more processing or computing systems, or similar devices, which operate and convert data represented as physical (e.g., electronic) quantities within registers or memories of a processing system into other data similarly represented as physical quantities within memories, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals may be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0157] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of protection of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0158] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly stated in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0159] Those skilled in the art will also appreciate that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in conjunction with the embodiments herein can all be implemented as electronic hardware, computer software, or a combination thereof. In order to clearly illustrate the interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above around their functions. Whether such functions are implemented as hardware or software depends on specific applications and the design constraints imposed on the entire system. A skilled person can implement the described functions in an alternative manner for each specific application, but such implementation decisions should not be interpreted as departing from the scope of protection of the present disclosure.

[0160] The steps of the method or algorithm described in conjunction with the embodiments herein may be directly embodied as hardware, a software module executed by a processor, or a combination thereof. The software module may be located in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a mobile disk, a CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor so that the processor can read information from the storage medium and can write information to the storage medium. Of course, the storage medium may also be an integral part of the processor. The processor and the storage medium may be located in an ASIC. The ASIC may be located in a user terminal. Of course, the processor and the storage medium may also be present in a user terminal as discrete components.

[0161] For software implementation, the techniques described in this application can be implemented with modules (e.g., procedures, functions, etc.) that perform the functions described in this application. These software codes can be stored in a memory unit and executed by a processor. The memory unit can be implemented within the processor or outside the processor. In the latter case, it is coupled to the processor in a communication manner via various means, which are well known in the art.

[0162] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," is explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

Claims

1. A method for constructing a biaxial anisotropic formation equivalent model, characterized in that: include: Constructing a one-dimensional horizontal layered biaxial anisotropic formation model, wherein the one-dimensional horizontal layered biaxial anisotropic formation model includes a plurality of first formations, wherein the parameters of the first formations include resistivity in the x-direction, the y-direction and the z-direction, and the first formations have resistivity anisotropy characteristics; the x-direction and the y-direction are two directions perpendicular to each other on a horizontal plane, and the z-direction is a direction perpendicular to the horizontal plane; Determine the values ​​of multiple equivalent parameters of each first stratum according to the resistivity values ​​of each first stratum in the x-direction, the y-direction and the z-direction, and obtain an equivalent model of each first stratum; The set of equivalent models of the first formations is taken as a biaxial anisotropic formation equivalent model.

2. The method according to claim 1, characterized in that The equivalent parameters include vertical resistivity and horizontal resistivity; The method of determining the values ​​of several equivalent parameters of each first stratum according to the resistivity values ​​of each first stratum in the x-direction, the y-direction and the z-direction to obtain the equivalent model of each first stratum includes: For each first stratum, taking the resistivity value of the first stratum in the z direction as the value of the vertical resistivity of the first stratum; Determining a value of horizontal resistivity of the first formation according to resistivity values ​​of the first formation in the x-direction and the y-direction; An equivalent model of the first formation is obtained according to the value of the vertical resistivity and the value of the horizontal resistivity of the first formation.

3. The method according to claim 2, characterized in that Determining the value of the horizontal resistivity of the first formation according to the resistivity values ​​of the first formation in the x-direction and the y-direction includes: Calculating the square root of the product of the resistivity values ​​of the first formation in the x direction and the y direction to obtain an initial resistivity value; In the case where the first formation has uniaxial anisotropy characteristics, taking the initial resistivity value as the value of the horizontal resistivity of the first formation; In the case that the first formation has a biaxial anisotropic characteristic, the biaxial anisotropic response of the first formation is determined, and the horizontal resistivity value of the first formation is determined based on the biaxial anisotropic response and the initial resistivity value.

4. The method according to claim 3, characterized in that Determining a value of horizontal resistivity of the first formation according to the biaxial anisotropic response and the initial resistivity value includes: According to the initial resistivity value, the uniaxial anisotropic response of the first formation is solved by using a uniform medium analytical formula; Calculate the fitting difference between the biaxial anisotropic response and the uniaxial anisotropic response, and determine whether the fitting difference is less than a preset fitting difference threshold; if so, use the initial resistivity value as the value of the horizontal resistivity of the first formation; if not, determine the value of the horizontal resistivity of the first formation based on the biaxial anisotropic response, the uniaxial anisotropic response and the initial resistivity value of the first formation.

5. The method according to claim 4, characterized in that Determining a value of horizontal resistivity of the first formation according to a biaxial anisotropic response, a uniaxial anisotropic response and the initial resistivity value of the first formation includes: updating the initial resistivity value by using an inversion algorithm according to the biaxial anisotropic response, the uniaxial anisotropic response and the initial resistivity value of the first formation; According to the updated initial resistivity value, the uniaxial anisotropic response is updated using a uniform medium analytical formula; According to the biaxial anisotropic response of the first formation, the updated uniaxial anisotropic response and the updated initial resistivity value, the initial resistivity value and the uniaxial anisotropic response are updated again by using an inversion algorithm, and the step of updating the initial resistivity value and the uniaxial anisotropic response again is repeatedly performed until the fitting difference between the updated uniaxial anisotropic response and the biaxial anisotropic response is greater than or equal to the fitting difference threshold; The initial resistivity value updated after the iteration is terminated is used as the horizontal resistivity of the first formation.

6. The method according to any one of claims 3 to 5, characterized in that: The biaxial anisotropic response of the first formation is determined by: determining a spatial domain magnetic field in a stratigraphic coordinate system of the first stratigraphic layer; Converting the spatial domain magnetic field in the formation coordinate system to the instrument coordinate system to obtain the spatial domain magnetic field in the instrument coordinate system; The product of the spatial domain magnetic field in the instrument coordinate system and the pre-acquired instrument coefficient is taken as the biaxial anisotropic response of the first formation.

7. The method according to claim 6, characterized in that The determining of the spatial domain magnetic field of the first formation in a formation coordinate system includes: Maxwell equations are used to perform Fourier transform along the x-direction, the y-direction and the z-direction. After the Fourier transform is completed, the spectral domain magnetic field of the first formation is solved to obtain an analytical expression of the spectral domain magnetic field; An inverse Fourier transform is performed on the spectral domain magnetic field analytical expression to obtain the spatial domain magnetic field in the formation coordinate system of the first formation.

8. The method according to claim 7, characterized in that The parameters of the first formation also include an inclination angle, which is a relative inclination angle between the tool axis and the first formation; The performing inverse Fourier transform on the spectral domain magnetic field analytical expression to obtain the spatial domain magnetic field in the formation coordinate system of the first formation includes: Perform inverse Fourier transform on the spectral domain magnetic field analytical expression to obtain the spatial domain magnetic field expression. Use the symmetry and antisymmetry laws of the spectral domain magnetic field in the four integral quadrants and the residue theorem to simplify the spatial domain magnetic field expression. When the degree of the inclination angle is less than a preset inclination angle threshold, a double Gauss-Legendre integral is used to solve the simplified spatial domain magnetic field expression to determine the spatial domain magnetic field in the formation coordinate system; When the degree of the inclination angle is greater than or equal to a preset inclination angle threshold, double sine-cosine filter integration is used to solve the simplified spatial domain magnetic field expression to determine the spatial domain magnetic field in the formation coordinate system.

9. The method according to claim 1, characterized in that The one-dimensional horizontal layered biaxial anisotropic stratum model also includes a plurality of second strata, and the second strata have isotropic characteristics.

10. A method for determining biaxial anisotropic formation response, characterized in that: include: Obtaining the resistivity values ​​and dip angles of each stratum in the target biaxial anisotropic stratum in the x-direction, y-direction and z-direction, and constructing a biaxial anisotropic stratum equivalent model corresponding to the target biaxial anisotropic stratum according to the resistivity values ​​and dip angles of each stratum in the x-direction, y-direction and z-direction, wherein the biaxial anisotropic stratum equivalent model is obtained by the method for constructing a biaxial anisotropic stratum equivalent model according to any one of claims 1 to 9; The response of the biaxial anisotropic formation equivalent model corresponding to the target formation is calculated to obtain the response of the target biaxial anisotropic formation.

11. A device for constructing a biaxial anisotropic formation equivalent model, characterized in that: include: A first construction module is used to construct a one-dimensional horizontal layered biaxial anisotropic formation model, wherein the one-dimensional horizontal layered biaxial anisotropic formation model includes a plurality of first formations, the parameters of the first formations include resistivity in the x-direction, the y-direction and the z-direction, and the first formations have resistivity anisotropy characteristics; the x-direction and the y-direction are two directions perpendicular to each other on a horizontal plane, and the z-direction is a direction perpendicular to the horizontal plane; The first determination module is used to determine the values ​​of multiple equivalent parameters of each first stratum according to the resistivity values ​​of each first stratum in the x-direction, the y-direction and the z-direction, respectively, to obtain an equivalent model of each first stratum, The second determination module is used to use the set of equivalent models of the first formations as a biaxial anisotropic formation equivalent model.

12. A device for determining biaxial anisotropic formation response, characterized in that: include: A second construction module is used to obtain the resistivity values ​​and the degree of inclination of each stratum in the target biaxial anisotropic stratum in the x-direction, y-direction and z-direction, and to construct a biaxial anisotropic stratum equivalent model corresponding to the target biaxial anisotropic stratum according to the resistivity values ​​and the degree of inclination of each stratum in the x-direction, y-direction and z-direction, wherein the biaxial anisotropic stratum equivalent model is obtained by the construction method of the biaxial anisotropic stratum equivalent model according to any one of claims 1 to 9; The calculation module is used to calculate the response of the biaxial anisotropic formation equivalent model corresponding to the target formation to obtain the response of the target biaxial anisotropic formation.

13. A computer storage medium, characterized in that: The computer storage medium stores computer executable instructions, which, when executed by a processor, implement a method for constructing a biaxial anisotropic formation equivalent model as described in any one of claims 1 to 9 or a method for determining a biaxial anisotropic formation response as described in claim 10.

14. A terminal device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method for constructing a biaxial anisotropic formation equivalent model as described in any one of claims 1 to 9 or the method for determining a biaxial anisotropic formation response as described in claim 10 is implemented.

15. A computer program product, characterized in that The computer program product includes a computer program, which, when executed by a processor, implements the method for constructing a biaxial anisotropic formation equivalent model as described in any one of claims 1 to 9 or the method for determining a biaxial anisotropic formation response as described in claim 10.

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