Rock physics modeling method and device, electronic equipment and storage medium

Abstract

The embodiment of the invention discloses a rock physical modeling method and device, electronic equipment and a storage medium. The method comprises the following steps: for a target rock to be subjected to rock physical modeling, determining a general mass change equation of pore fluid in any pore space in the target rock in unit time; according to the matrix pores in the target rock, the pore volume of the matrix pores and the pore fluid pressure borne by pore fluid in the matrix pores are determined, and the pore volume and the pore fluid pressure are related to the matrix pore shapes of the matrix pores; according to the general mass change equation, the pore volume and the pore fluid pressure, a pore mass change equation of the pore fluid in the matrix pores in unit time is obtained; and establishing a rock physical model of the target rock according to the pore mass change equation. According to the technical scheme provided by the embodiment of the invention, the rock physical model capable of accurately analyzing the influence of the rock physical property on the elastic property can be established.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of oil and gas reservoir exploration, and in particular to a rock physics modeling method, device, electronic equipment and storage medium. Background Art

[0002] Seismic rock physics is the bridge between rock physical parameters and rock elastic parameters.

[0003] On this basis, rock physics modeling is to establish the correspondence between rock physical parameters and rock elastic parameters through mathematical relationships, which helps to achieve mutual derivation between the two parameters, and further effectively quantitatively analyze the influence of rock physical properties on elastic properties, which is of great significance to the exploration and development of oil and gas reservoirs.

[0004] However, the rock physics models currently established are not very reasonable and cannot accurately analyze the impact of rock physical properties on elastic properties, and need to be improved. Summary of the invention

[0005] The embodiments of the present invention provide a rock physics modeling method, device, electronic device and storage medium to establish a rock physics model that can accurately analyze the influence of rock physical properties on elastic properties.

[0006] According to one aspect of the present invention, a rock physics modeling method is provided, which may include:

[0007] For the target rock to be subjected to rock physics modeling, a universal mass change equation of the pore fluid in any pore space in the target rock per unit time is determined;

[0008] For the matrix pores in the target rock, the pore volume of the matrix pores and the pore fluid pressure of the pore fluid in the matrix pores are determined, wherein the pore volume and the pore fluid pressure are related to the matrix pore shape of the matrix pores;

[0009] According to the general mass change equation, pore volume and pore fluid pressure, the pore mass change equation of the pore fluid in the matrix pores per unit time is obtained;

[0010] According to the pore mass variation equation, a rock physics model of the target rock is established.

[0011] According to another aspect of the present invention, a rock physics modeling device is provided, which may include:

[0012] A universal mass change equation determination module is used to determine the universal mass change equation of the pore fluid in any pore space in the target rock to be subjected to rock physics modeling per unit time;

[0013] A pore fluid pressure determination module is used to determine the pore volume of the matrix pores and the pore fluid pressure of the pore fluid in the matrix pores for the matrix pores in the target rock, wherein the pore volume and the pore fluid pressure are related to the matrix pore shape of the matrix pores;

[0014] A pore mass change equation obtaining module is used to obtain the pore mass change equation of the pore fluid in the matrix pores per unit time according to the general mass change equation, the pore volume and the pore fluid pressure;

[0015] The rock physics modeling module is used to establish a rock physics model of the target rock based on the pore mass change equation.

[0016] According to another aspect of the present invention, there is provided an electronic device, which may include:

[0017] at least one processor; and

[0018] a memory communicatively connected to at least one processor; wherein,

[0019] The memory stores a computer program that can be executed by at least one processor. The computer program can be executed by at least one processor so that the rock physics modeling method provided by any embodiment of the present invention is implemented when the at least one processor executes the computer program.

[0020] According to another aspect of the present invention, a computer-readable storage medium is provided, on which computer instructions are stored. The computer instructions are used to enable a processor to implement the rock physics modeling method provided by any embodiment of the present invention when executed.

[0021] The technical solution of the embodiment of the present invention is to determine the universal mass change equation of the pore fluid in any pore space in the target rock per unit time for the target rock to be subjected to rock physics modeling; for the matrix pores in the target rock, determine the pore volume of the matrix pores and the pore fluid pressure to which the pore fluid in the matrix pores is subjected, wherein the pore volume and the pore fluid pressure are related to the pore shape of the matrix pores; obtain the pore mass change equation of the pore fluid in the matrix pores per unit time according to the universal mass change equation, the pore volume and the pore fluid pressure; and establish a rock physics model of the target rock according to the pore mass change equation. The above technical solution can establish a rock physics model containing any matrix pore shape, thereby eliminating the error caused by the spherical matrix pores, thereby achieving the effect of accurately analyzing the influence of rock physical properties on elastic properties using a rock physics model.

[0022] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 is a flow chart of a rock physics modeling method provided according to an embodiment of the present invention;

[0025] Figure 2 is a flow chart of another rock physics modeling method provided according to an embodiment of the present invention;

[0026] Figure 3 is a flow chart of another rock physics modeling method provided according to an embodiment of the present invention;

[0027] Figure 4 is a flow chart of another rock physics modeling method provided according to an embodiment of the present invention;

[0028] Figure 5 is a schematic diagram of an optional example of another rock physics modeling method provided according to an embodiment of the present invention;

[0029] Figure 6a In another rock physics modeling method provided in an embodiment of the present invention, when the Lame constant and the shear modulus are fixed, the pore aspect ratio change and the σ when the pore aspect ratio is fixed are analyzed. p Schematic diagram of the results;

[0030] Figure 6b In another rock physics modeling method provided by an embodiment of the present invention, when the Lame constant and the shear modulus are fixed, the pore aspect ratio σ is analyzed and considered. p Schematic diagram of the results compared to the change rate when the pore aspect ratio is not considered;

[0031] Figure 6c In another rock physics modeling method provided in an embodiment of the present invention, when the Lame constant and the shear modulus are fixed, the K of the pore aspect ratio change and the pore aspect ratio when the pore aspect ratio is fixed are analyzed. p Schematic diagram of the results;

[0032] Figure 6dIn another rock physics modeling method provided by an embodiment of the present invention, when the Lame constant and the shear modulus are fixed, K is analyzed considering the pore aspect ratio. p Schematic diagram of the results compared to the change rate when the pore aspect ratio is not considered;

[0033] Figure 7a The method for analyzing the influence of matrix pore shape change on the stiffness parameter C in another rock physics modeling method provided by an embodiment of the present invention is 11 Schematic diagram of the results of the impact of

[0034] Figure 7b The method for analyzing the influence of matrix pore shape change on the stiffness parameter C in another rock physics modeling method provided by an embodiment of the present invention is 12 Schematic diagram of the results of the impact of

[0035] Figure 7c The method for analyzing the influence of matrix pore shape change on the stiffness parameter C in another rock physics modeling method provided by an embodiment of the present invention is 33 Schematic diagram of the results of the impact of

[0036] Figure 7d The method for analyzing the influence of matrix pore shape change on the stiffness parameter C in another rock physics modeling method provided by an embodiment of the present invention is 13 Schematic diagram of the results of the impact of

[0037] Figure 8a It is a schematic diagram of the results of analyzing the influence of matrix pore shape changes on the horizontal longitudinal wave velocity in another rock physics modeling method provided by an embodiment of the present invention;

[0038] Figure 8b It is a schematic diagram of the results of analyzing the influence of matrix pore shape changes on the longitudinal wave velocity in the vertical direction in another rock physics modeling method provided by an embodiment of the present invention;

[0039] Figure 9a It is a schematic diagram of the results of comparing different rock physics models predicting the horizontal longitudinal wave velocity using laboratory measurement data in another rock physics modeling method provided by an embodiment of the present invention;

[0040] Figure 9b It is a schematic diagram of the results of comparing different rock physics models to predict the longitudinal wave velocity in the vertical direction using laboratory measurement data in another rock physics modeling method provided by an embodiment of the present invention;

[0041] Fig.10 is a structural block diagram of a rock physics modeling device provided according to an embodiment of the present invention;

[0042] Fig.11It is a schematic diagram of the structure of an electronic device for implementing the rock physics modeling method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0044] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. The situations of "target", "original", etc. are similar and will not be repeated here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0045] Before introducing the embodiments of the present invention, the research and development ideas of the embodiments of the present invention are first exemplified, so as to better understand the rock physics model established by the embodiments of the present invention, and the reasons why the rock physical properties can be accurately analyzed for the influence of the elastic properties. For example, underground rocks often contain a variety of pore types. In practical applications, the pore types can be classified into three categories according to factors such as pore shape and the orientation of the long axis of the pores: matrix pores, random fractures (i.e., randomly distributed fractures) and directional fractures (i.e., directional arranged fractures). For matrix pores, the rock physics model currently established assumes that the pore aspect ratio of all matrix pores is 1, that is, the matrix pore shape of all matrix pores is spherical, which is obviously inconsistent with the actual situation and has poor rationality, so that the rock physics model cannot accurately analyze the influence of rock physical properties on elastic properties.

[0046] In view of this, it is assumed that the underground rock is subjected to external pressure, and the compressive strength of matrix pores with different matrix pore shapes is different. This is the theoretical basis of rock physics models with different matrix pore shapes. In the process of rock physics modeling, the pore fluids contained in matrix pores, random fractures and directional fractures can flow between pores of different pore types. By considering any matrix pore shape, the influence of rock physical properties on elastic properties can be more reasonably analyzed.

[0047] Figure 1 1 is a flow chart of a rock physics modeling method provided by an embodiment of the present invention. This embodiment is applicable to rock physics modeling, and is particularly applicable to establishing a rock physics model under consideration of any matrix pore shape. The method can be executed by a rock physics modeling device provided by an embodiment of the present invention, which can be implemented by software and / or hardware, and can be integrated on an electronic device, which can be various user terminals or servers.

[0048] See also Figure 1 The method of the embodiment of the present invention specifically includes the following steps:

[0049] S110. For a target rock to be subjected to rock physics modeling, a universal mass change equation of a pore fluid in any pore space in the target rock per unit time is determined.

[0050] Among them, the target rock can be understood as the rock to be subjected to rock physics modeling. The pore space can be understood as the space where the pores in the target rock are located. In combination with the application scenarios that may be involved in the embodiments of the present invention, the pores may be caused by matrix pores or cracks (for example, random cracks or directional cracks) in the target rock. The number of pore spaces can be one, two or more, which is related to the actual situation and is not specifically limited here. The pore fluid can be understood as the fluid flowing in the pore space. The general mass change equation can be used to describe the mass change law of the pore fluid in any pore space per unit time. It is not for matrix pores, random cracks or directional cracks, so it has a certain degree of universality.

[0051] Determine the universal mass change equation per unit time for the pore fluid in any pore space in the target rock.

[0052] S120. Determine the pore volume of the matrix pores and the pore fluid pressure to which the pore fluid in the matrix pores is subjected for the matrix pores in the target rock, wherein the pore volume and the pore fluid pressure are related to the matrix pore shape of the matrix pores.

[0053] Among them, the pore volume can be understood as the volume of matrix pores; the pore fluid pressure can be understood as the pressure exerted on the pore fluid in the matrix pores; the matrix pore shape can be understood as the shape of the matrix pores. In practical applications, the matrix pore shape can be optionally represented by the pore aspect ratio of the matrix pores. It should be noted that since the rock physics model established in the embodiment of the present invention considers any matrix pore shape, the pore volume and pore fluid pressure are both related to the matrix pore shape.

[0054] Determine the pore volume and pore fluid pressure.

[0055] S130. According to the general mass change equation, the pore volume and the pore fluid pressure, the pore mass change equation of the pore fluid in the matrix pores per unit time is obtained.

[0056] Among them, since any pore space includes the pore space where the matrix pores are located, the pore mass change equation of the pore fluid in the matrix pores per unit time can be obtained according to the general mass change equation, the pore volume and the pore fluid pressure. The pore mass change equation can be used to describe the mass change law of the pore fluid in the matrix pores per unit time.

[0057] S140. Establish a rock physics model of the target rock based on the pore mass variation equation.

[0058] Among them, since the pore mass variation equation takes into account the arbitrary matrix pore shape, a rock physics model of the target rock containing arbitrary matrix pore shape can be established based on the pore mass variation equation, thereby eliminating the error caused by spherical matrix pores, thereby achieving the effect of using the rock physics model to accurately analyze the influence of rock physical properties on elastic properties.

[0059] The technical solution of the embodiment of the present invention is to determine the universal mass change equation of the pore fluid in any pore space in the target rock per unit time for the target rock to be subjected to rock physics modeling; for the matrix pores in the target rock, determine the pore volume of the matrix pores and the pore fluid pressure to which the pore fluid in the matrix pores is subjected, wherein the pore volume and the pore fluid pressure are related to the pore shape of the matrix pores; obtain the pore mass change equation of the pore fluid in the matrix pores per unit time according to the universal mass change equation, the pore volume and the pore fluid pressure; and establish a rock physics model of the target rock according to the pore mass change equation. The above technical solution can establish a rock physics model containing any matrix pore shape, thereby eliminating the error caused by the spherical matrix pores, thereby achieving the effect of accurately analyzing the influence of rock physical properties on elastic properties using a rock physics model.

[0060] Figure 2It is a flow chart of another rock physics modeling method provided in an embodiment of the present invention. This embodiment is optimized based on the above-mentioned technical solutions. In this embodiment, optionally, the above-mentioned rock physics modeling method may also include: for the cracks in the target rock, according to the general mass change equation, obtaining the crack mass change equation of the pore fluid in the crack per unit time, wherein the crack is a random crack and / or a directional crack; according to the pore mass change equation, establishing a rock physics model of the target rock, which may include: constructing a mass conservation equation according to the law of conservation of mass, the pore mass change equation and the crack mass change equation; according to the mass conservation equation, establishing a rock physics model of the target rock. Among them, the explanations of the terms that are the same or corresponding to the above-mentioned embodiments are not repeated here.

[0061] See also Figure 2 The method of this embodiment may specifically include the following steps:

[0062] S210. For the target rock to be subjected to rock physics modeling, determine a universal mass change equation per unit time for the pore fluid in any pore space in the target rock.

[0063] S220. Determine the pore volume of the matrix pores and the pore fluid pressure to which the pore fluid in the matrix pores is subjected for the matrix pores in the target rock, wherein the pore volume and the pore fluid pressure are related to the matrix pore shape of the matrix pores.

[0064] S230. According to the general mass change equation, the pore volume and the pore fluid pressure, the pore mass change equation of the pore fluid in the matrix pores per unit time is obtained.

[0065] S240. For cracks in the target rock, a crack mass change equation of the pore fluid in the crack per unit time is obtained according to a general mass change equation, wherein the cracks are random cracks and / or directional cracks.

[0066] Among them, for the cracks in the target rock, since any pore space includes the space where the cracks are located, the fracture mass change equation of the pore fluid in the fracture per unit time can be obtained according to the general mass change equation. The fracture mass change equation can be used to describe the mass change law of the pore fluid in the fracture per unit time.

[0067] S250, constructing a mass conservation equation based on the mass conservation law, the pore mass change equation and the fracture mass change equation, and establishing a rock physics model of the target rock based on the mass conservation equation.

[0068] Among them, since the pore fluid flow between pores of different pore types in the target rock follows the law of conservation of mass, the mass conservation equation can be constructed based on the law of conservation of mass, the pore mass change equation and the fracture mass change equation, and then the rock physics model can be established based on the mass conservation equation.

[0069] The technical solution of the embodiment of the present invention can establish a rock physics model containing matrix pores and fractures under any matrix pore shape by determining the fracture mass change equation corresponding to the fracture and combining it with the law of conservation of mass.

[0070] An optional technical solution, based on the mass conservation equation, establishes a rock physics model of the target rock, which may include: combining the pore mass change equation, the fracture mass change equation and the mass conservation equation to obtain the pore pressure in the matrix pores and the fracture pressure in the fractures; and establishing the rock physics model of the target rock based on the pore pressure and the fracture pressure. The above technical solution realizes the effective establishment of the rock physics model by determining the pore pressure and the fracture pressure.

[0071] On this basis, according to the pore pressure and the fracture pressure, a rock physics model of the target rock is established, including: calculating the stiffness parameter according to the pore pressure and the fracture pressure; and establishing the rock physics model of the target rock according to the stiffness parameter. The above technical solution can effectively characterize the rock physics model through the stiffness parameter.

[0072] Figure 3 It is a flow chart of another rock physics modeling method provided by an embodiment of the present invention. This embodiment is optimized based on the above-mentioned technical solutions. In this embodiment, optionally, when the fractures are random fractures and directional fractures, the fracture mass change equation includes the random fracture mass change equation and the directional fracture mass change equation, and the mass conservation equation is constructed according to the mass conservation law, the pore mass change equation and the fracture mass change equation, including: constructing the mass conservation equation according to the mass conservation law, the pore mass change equation, the random fracture mass change equation and the directional fracture mass change equation. Among them, the explanations of the terms that are the same or corresponding to the above-mentioned embodiments are not repeated here.

[0073] See also Figure 3 The method of this embodiment may specifically include the following steps:

[0074] S310. For the target rock to be subjected to rock physics modeling, determine a universal mass change equation per unit time for the pore fluid in any pore space in the target rock.

[0075] S320. For matrix pores in the target rock, determine the pore volume of the matrix pores and the pore fluid pressure to which the pore fluid in the matrix pores is subjected, wherein the pore volume and the pore fluid pressure are related to the matrix pore shape of the matrix pores.

[0076] S330. According to the general mass change equation, the pore volume and the pore fluid pressure, the pore mass change equation of the pore fluid in the matrix pores per unit time is obtained.

[0077] S340. For random fractures in the target rock, a random fracture mass change equation of the pore fluid in the random fracture per unit time is obtained according to a general mass change equation.

[0078] S350. For the directional cracks in the target rock, according to the general mass change equation, a directional crack mass change equation of the pore fluid in the directional crack per unit time is obtained.

[0079] S360. Based on the law of conservation of mass, the pore mass change equation, the random crack mass change equation and the directional crack mass change equation, a mass conservation equation is constructed.

[0080] S370. Based on the mass conservation equation, a rock physics model of the target rock is established.

[0081] The technical solution of the embodiment of the present invention can establish a rock physics model including matrix pores, random fractures and directional fractures under any matrix pore shape by determining the random fracture mass change equation corresponding to the random fracture and the directional fracture mass change equation corresponding to the directional fracture.

[0082] Figure 4 It is a flow chart of another rock physics modeling method provided in an embodiment of the present invention. This embodiment is optimized based on the above technical solutions. In this embodiment, optionally, the above rock physics modeling method may also include: obtaining the rock density of the target rock, and calculating the horizontal and / or vertical longitudinal wave velocity in the target rock according to the rock density and the rock physics model. Among them, the explanations of the terms that are the same or corresponding to the above embodiments are not repeated here.

[0083] See also Figure 4 The method of this embodiment may specifically include the following steps:

[0084] S410. For the target rock to be subjected to rock physics modeling, determine a universal mass change equation per unit time for the pore fluid in any pore space in the target rock.

[0085] S420. For matrix pores in the target rock, determine the pore volume of the matrix pores and the pore fluid pressure to which the pore fluid in the matrix pores is subjected, wherein the pore volume and the pore fluid pressure are related to the matrix pore shape of the matrix pores.

[0086] S430. According to the general mass change equation, the pore volume and the pore fluid pressure, the pore mass change equation of the pore fluid in the matrix pores per unit time is obtained.

[0087] S440. Based on the pore mass variation equation, a rock physics model of the target rock is established.

[0088] S450: Obtain the rock density of the target rock, and calculate the longitudinal wave velocity in the target rock in the horizontal direction and / or vertical direction according to the rock density and the rock physics model.

[0089] Among them, rock density can be understood as the density of the target rock. According to the rock density and rock physics model, the horizontal and / or vertical P-wave velocity in the target rock is calculated, which helps to analyze the influence of matrix pore shape on P-wave velocity, that is, to analyze the influence of matrix pore shape on seismic wave velocity.

[0090] The technical solution of the embodiment of the present invention analyzes the P-wave velocity through the established rock physics model, thereby obtaining the influence of the matrix pore shape on the P-wave velocity.

[0091] In order to better understand the above-mentioned technical solutions as a whole, the following is an exemplary description with reference to specific examples. Figure 5 First, according to the elastic modulus of matrix minerals, the elastic modulus of pore fluids, and the parameters such as pore length and pore aspect ratio under different pore types, the mass change equation (i.e., flow equation) of the mutual flow of pore fluids between different pore types is calculated, and then the stiffness parameters of saturated rocks are calculated using the law of conservation of mass and Eshelby theory. Then, the stiffness parameters are used to calculate the seismic wave velocity, and the influence of any matrix pore shape on the seismic wave velocity is analyzed. The specific steps are as follows:

[0092] (1) Assume that the mutual flow of pore fluid in one pore space a and another pore space b per unit time follows the following relationship, that is, the general mass change equation is shown in the following formula (1):

[0093]

[0094] in, represents the mass change of the pore fluid in the pore space a per unit time; ρ0 represents the density of the pore fluid; k represents the permeability; represents the particle size; η represents the pore fluid velocity; p arepresents the pressure in the pore space a; p b Represents the pressure in the pore space b.

[0095] (2) According to formula (1), the variation law of the pore fluid in the matrix pores per unit time (i.e., the pore mass variation equation), the variation law of the pore fluid in the random fractures per unit time (i.e., the random fracture mass variation equation), and the variation law of the pore fluid in the directional fractures per unit time (i.e., the directional fracture mass variation equation) can be obtained respectively:

[0096]

[0097]

[0098]

[0099] in,

[0100] Formula (2) represents the pore fluid flow in a single matrix pore, p * is the matrix pore pressure (i.e. the pore pressure mentioned above), σ ii is the pressure acting on the matrix pore surface; is Poisson's ratio. When the sign on the right side of the equation is positive, it means the fluid outside the pore flows in, and when it is negative, it means the fluid inside the pore flows out. v represents the pore volume of a single matrix pore. Since the matrix pore shape is taken into account in this example, r p is the pore radius, α p is the pore aspect ratio; σ p is the pore fluid pressure (i.e., the pressure on the pore fluid in the matrix pores);

[0101] Formula (3) represents the pore fluid flow in a single random fracture, p i represents the pressure inside the random fracture, σ i is the surface pressure acting on the random crack; c v is the fracture volume of a single random fracture, r c is the crack radius, α c is the crack aspect ratio; σ c is the random fracture fluid pressure (i.e., the pressure on the pore fluid in the random fracture);

[0102] Formula (4) represents the pore fluid flow in a single directional fracture, f is the pressure in the directional fracture, σ f is the surface pressure acting on the directional crack; f v represents the fracture volume of a single directional fracture, r f is the crack radius, α fis the crack aspect ratio; σ f is the directional fracture fluid pressure (i.e., the pressure on the pore fluid in the directional fracture);

[0103] It should be noted that since this example considers arbitrary matrix pore shapes, as well as as well as These variables are all coefficients, K fluid is the bulk modulus of the pore fluid. Since the pore aspect ratio of the fracture pores is very small compared to the pore aspect ratio of the matrix pores, α can be c =α f , and then we have σ c =σ f , K c =K f .

[0104] (3) The fluid flow between pores of different pore types in the target rock follows the law of conservation of mass:

[0105]

[0106] Where N is the total amount of various pores, N c is the total amount of random cracks, N f is the total amount of directional cracks; assuming N f <<N c .

[0107] (4) Combining equations (2), (3), (4) and (5), we can obtain the matrix pore pressure p * , random crack internal pressure p i And the pressure f in the directional fracture. It should be noted that the variables on the right side of equations (6), (7) and (8) all include variables related to the pore type:

[0108]

[0109]

[0110]

[0111] in,

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119] in, φ f represents the porosity of directional fractures, φ p represents the porosity of the matrix pores, φ c represents the porosity of random fractures; c1 represents a single random crack connected to c1 other pores, and c2 represents a single directional crack connected to c2 other pores. In practical applications, it can be assumed that c1=c2=2.

[0120] (5) According to the Eshelby theory, and assuming that the directional crack is in a vertical horizontal transverse isotropy (HTI) medium, the stiffness parameters are calculated. Equations (16) to (20) are the specific process of calculating the stiffness parameters according to the Eshelby theory:

[0121]

[0122] Depending on the pore type, the second term on the right side of the equation can be written as:

[0123]

[0124]

[0125]

[0126] Substitute equations (17), (18) and (19) into equation (16), where C 11 For example, there are:

[0127]

[0128] On this basis, each stiffness parameter (C 11 , C 12 , C 33 and C 13 ) is as follows:

[0129]

[0130]

[0131]

[0132]

[0133] in,

[0134]

[0135]

[0136] in, is the bulk modulus of the matrix mineral, and μ is the shear modulus of the matrix mineral.

[0137] (6) Based on the stiffness parameter, calculate the horizontal longitudinal wave velocity V Ph and the longitudinal wave velocity V in the vertical direction Pv :

[0138]

[0139]

[0140] where ρ is the rock density.

[0141] The above example fully considers the arbitrary matrix pore shape and establishes a rock physics model including matrix pores, random fractures and directional fractures. It can be said to be a fracture-pore type anisotropic medium rock physics model. On this basis, a series of experimental analyses were carried out on this rock physics model, which proved the effectiveness of the rock physics model and the influence of matrix pore shape on P-wave velocity. The specific experimental results are shown below.

[0142] Figure 6a-6d is to analyze the σ when the pore aspect ratio changes and the pore aspect ratio is fixed when the Lame constant and shear modulus are fixed. p and K p Schematic diagram of the results, from which we can see that compared with the case where the pore aspect ratio is fixed, the change in pore aspect ratio has a greater effect on σ p and K p The impact is more obvious. Specifically, Figure 6a The solid line in the figure is the Lamé constant and the shear modulus are both given as 17.5 GPa and the fluid bulk modulus K f When the matrix pore σ is 2 GPa, p As the pore aspect ratio changes, the dashed line is the case of a given pore aspect ratio; Figure 6b is σ considering the pore aspect ratio p , compared with the rate of change when the pore aspect ratio is not considered; Figure 6c The solid line in the middle is the K of the matrix pores. p As the pore aspect ratio changes, the dashed line is the case of a given pore aspect ratio; Figure 6d is K considering the pore aspect ratio p, compared with the rate of change when the pore aspect ratio is not considered.

[0143] Figure 7a-7d It is to analyze the influence of the change of matrix pore shape (i.e. pore aspect ratio) on different stiffness parameters. As can be seen from the figure, the stiffness parameter increases with the increase of pore aspect ratio, and the influence of pore aspect ratio change on stiffness parameter is more obvious.

[0144] Figure 8a It is to analyze the influence of the change of matrix pore shape on the horizontal longitudinal wave velocity. Figure 8b It is to analyze the influence of the change of matrix pore shape on the longitudinal wave velocity in the vertical direction. It can be seen from the figure that the longitudinal wave velocity increases with the increase of matrix pore shape (i.e. pore aspect ratio), and the influence of matrix pore shape on the longitudinal wave velocity is more obvious.

[0145] Figure 9a and Figure 9b The laboratory measurement data is used to compare the rock physics model based on this example that takes into account the arbitrary matrix pore shape and the rock physics model based on the prior art that does not take into account the arbitrary matrix pore shape. Specifically, Figure 9a shows the horizontal longitudinal wave velocity, Figure 9b The longitudinal wave velocity in the vertical direction is shown, where the solid points are laboratory measurement data, the straight line is the prediction result corresponding to this example, and the dotted line is the prediction result corresponding to the prior art. It can be seen from the figure that compared with the prior art, the prediction result of this example is in good agreement with the laboratory measurement data.

[0146] Fig.10 This is a structural block diagram of a rock physics modeling device provided in an embodiment of the present invention, and the device is used to execute the rock physics modeling method provided in any of the above embodiments. The device and the rock physics modeling method of the above embodiments belong to the same inventive concept. For details not described in detail in the embodiments of the rock physics modeling device, please refer to the embodiments of the above rock physics modeling method. Fig.10 The device may specifically include: a general mass change equation determination module 510, a pore fluid pressure determination module 520, a pore mass change equation acquisition module 530 and a rock physics modeling module 540. Among them,

[0147] The universal mass change equation determination module 510 is used to determine the universal mass change equation of the pore fluid in any pore space in the target rock for rock physics modeling per unit time;

[0148] The pore fluid pressure determination module 520 is used to determine the pore volume of the matrix pores and the pore fluid pressure of the pore fluid in the matrix pores for the matrix pores in the target rock, wherein the pore volume and the pore fluid pressure are related to the matrix pore shape of the matrix pores;

[0149] A pore mass change equation obtaining module 530 is used to obtain a pore mass change equation of the pore fluid in the matrix pores per unit time according to the general mass change equation, the pore volume and the pore fluid pressure;

[0150] The rock physics modeling module 540 is used to establish a rock physics model of the target rock according to the pore mass variation equation.

[0151] Optionally, the rock physics modeling device further comprises:

[0152] A fracture mass change equation obtaining module is used to obtain a fracture mass change equation of pore fluid in the fracture per unit time according to a general mass change equation for fractures in target rocks, wherein the fractures are random fractures and / or directional fractures;

[0153] The rock physics modeling module 540 includes:

[0154] The mass conservation equation construction submodule is used to construct the mass conservation equation according to the mass conservation law, the pore mass change equation and the crack mass change equation;

[0155] The rock physics model establishment submodule is used to establish a rock physics model of the target rock according to the mass conservation equation.

[0156] On this basis, an optional rock physics model building submodule includes:

[0157] The unit for obtaining the intra-fracture pressure is used to simultaneously solve the pore mass change equation, the fracture mass change equation and the mass conservation equation to obtain the intra-pore pressure in the matrix pores and the intra-fracture pressure in the fractures;

[0158] The rock physics model building unit is used to build a rock physics model of the target rock according to the pore pressure and the fracture pressure.

[0159] On this basis, the optional rock physics model building unit is specifically used to:

[0160] Calculate the stiffness parameters based on the pore pressure and the fracture pressure;

[0161] According to the stiffness parameters, a rock physics model of the target rock is established.

[0162] Alternatively, in the case where the cracks are random cracks and directional cracks, the crack mass change equation includes the random crack mass change equation and the directional crack mass change equation;

[0163] The mass conservation equation building submodule includes:

[0164] The mass conservation equation construction unit can be used to construct the mass conservation equation according to the mass conservation law, the pore mass change equation, the random crack mass change equation and the directional crack mass change equation.

[0165] Based on any of the above devices, optionally, the device further includes:

[0166] The longitudinal wave velocity calculation module is used to obtain the rock density of the target rock and calculate the longitudinal wave velocity in the horizontal direction and / or vertical direction in the target rock according to the rock density and the rock physics model.

[0167] Based on any of the above devices, optionally, the matrix pore shape is represented by the pore aspect ratio of the matrix pores.

[0168] The rock physics modeling device provided by the embodiment of the present invention determines the universal mass change equation of the pore fluid in any pore space in the target rock per unit time through the universal mass change equation determination module for the target rock to be subjected to rock physics modeling; determines the pore volume of the matrix pores and the pore fluid pressure of the pore fluid in the matrix pores for the matrix pores in the target rock through the pore fluid pressure determination module, wherein the pore volume and the pore fluid pressure are both related to the pore shape of the matrix pores; obtains the pore mass change equation of the pore fluid in the matrix pores per unit time according to the universal mass change equation, the pore volume and the pore fluid pressure through the pore mass change equation obtaining module; and establishes a rock physics model of the target rock according to the pore mass change equation through the rock physics modeling module. The above device can establish a rock physics model containing any matrix pore shape, thereby eliminating the error caused by the spherical matrix pores, thereby achieving the effect of accurately analyzing the influence of rock physical properties on elastic properties using rock physics models.

[0169] The rock physics modeling device provided in the embodiment of the present invention can execute the rock physics modeling method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0170] It is worth noting that in the embodiment of the above-mentioned rock physics modeling device, the various units and modules included are only divided according to functional logic, but are not limited to the above-mentioned division, as long as the corresponding functions can be achieved; in addition, the specific names of the functional units are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention.

[0171] Fig.11 A schematic diagram of the structure of an electronic device 10 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0172] like Fig.11 As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0173] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0174] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as a rock physics modeling method.

[0175] In some embodiments, the rock physics modeling method may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the rock physics modeling method described above may be performed. Alternatively, in other embodiments, the processor 11 may be configured to perform the rock physics modeling method in any other suitable manner (e.g., by means of firmware).

[0176] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0177] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine as a stand-alone software package and partially on a remote machine, or entirely on a remote machine or server.

[0178] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0179] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0180] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0181] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0182] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0183] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A rock physics modeling method, characterized in that: include: For a target rock to be subjected to rock physics modeling, determining a universal mass change equation per unit time for a pore fluid in any pore space of the target rock; For the matrix pores in the target rock, determining the pore volume of the matrix pores and the pore fluid pressure to which the pore fluid in the matrix pores is subjected, wherein the pore volume and the pore fluid pressure are related to the matrix pore shape of the matrix pores; According to the general mass change equation, the pore volume and the pore fluid pressure, a pore mass change equation of the pore fluid in the matrix pores per unit time is obtained; According to the pore mass variation equation, a rock physics model of the target rock is established.

2. The method according to claim 1, characterized in that Also includes: For the cracks in the target rock, according to the general mass change equation, a crack mass change equation of the pore fluid in the cracks per unit time is obtained, wherein the cracks are random cracks and / or directional cracks; The step of establishing a rock physics model of the target rock according to the pore mass variation equation includes: According to the law of conservation of mass, the pore mass change equation and the crack mass change equation, a mass conservation equation is constructed; According to the mass conservation equation, a rock physics model of the target rock is established.

3. The method according to claim 2, characterized in that The step of establishing a rock physics model of the target rock according to the mass conservation equation includes: The pore mass change equation, the crack mass change equation and the mass conservation equation are combined to obtain the pore pressure in the matrix pores and the crack pressure in the cracks; A rock physics model of the target rock is established based on the pore pressure and the fracture pressure.

4. The method according to claim 3, characterized in that The step of establishing a rock physics model of the target rock according to the pore pressure and the fracture pressure includes: Calculating a stiffness parameter according to the pore pressure and the fracture pressure; A rock physics model of the target rock is established according to the stiffness parameters.

5. The method according to claim 2, characterized in that: In the case where the cracks are the random cracks and the directional cracks, the crack mass change equation includes the random crack mass change equation and the directional crack mass change equation, and the mass conservation equation is constructed according to the mass conservation law, the pore mass change equation and the crack mass change equation, including: A mass conservation equation is constructed according to the law of mass conservation, the pore mass change equation, the random crack mass change equation and the directional crack mass change equation.

6. The method according to any one of claims 1 to 5, characterized in that Also includes: The rock density of the target rock is obtained, and the longitudinal wave velocity in the horizontal direction and / or vertical direction in the target rock is calculated according to the rock density and the rock physics model.

7. The method according to any one of claims 1 to 5, characterized in that The matrix pore shape is represented by the pore aspect ratio of the matrix pores.

8. A rock physics modeling device, characterized in that: include: A universal mass change equation determination module is used to determine the universal mass change equation of the pore fluid in any pore space in the target rock to be subjected to rock physics modeling per unit time; A pore fluid pressure determination module is used to determine the pore volume of the matrix pores and the pore fluid pressure of the pore fluid in the matrix pores for the matrix pores in the target rock, wherein the pore volume and the pore fluid pressure are related to the matrix pore shape of the matrix pores; A pore mass change equation obtaining module, used to obtain a pore mass change equation of the pore fluid in the matrix pores per unit time according to the general mass change equation, the pore volume and the pore fluid pressure; The rock physics modeling module is used to establish a rock physics model of the target rock according to the pore mass variation equation.

9. An electronic device, characterized in that: include: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to perform the rock physical modeling method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to implement the rock physical modeling method as described in any one of claims 1-7 when executed by a processor.

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