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 rock matrix modulus of the target rock; according to the rock physical property parameters of the target rock, irreducible water saturation of irreducible water in the target rock is predicted, and the isolated porosity of the target rock is obtained according to the irreducible water saturation; and based on the isolated porosity, adjusting the matrix modulus of the rock, and based on the adjusted matrix modulus obtained after adjustment, establishing a rock physical model of the target rock. According to the technical scheme provided by the embodiment of the invention, in the rock physical modeling process, the influence of the complex pore connectivity and the irreducible water saturation on the rock elastic parameters is considered, so that the characterization accuracy of the rock physical model established by the method on the rock elastic parameters can be effectively improved.

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 a bridge between rock physical parameters and rock elastic parameters. Rock physics modeling is to establish the corresponding relationship between rock physical parameters and rock elastic parameters through mathematical relationships, which helps to achieve mutual derivation between the two parameters, and then effectively quantitatively analyze the impact of changes in rock physical parameters on rock elastic parameters, which is of great significance to the exploration and development of oil and gas reservoirs.

[0003] In the process of realizing the present invention, the inventors found that the prior art has the following technical problems: the currently established rock physics model cannot accurately predict rock elastic parameters and needs to be improved. Summary of the invention

[0004] The embodiments of the present invention provide a rock physics modeling method, device, electronic device and storage medium, which solve the problem that the established rock physics model cannot accurately predict rock elastic parameters.

[0005] According to one aspect of the present invention, a rock physics modeling method is provided, which may include:

[0006] For a target rock to be subjected to rock physics modeling, determining the rock matrix modulus of the target rock;

[0007] According to the petrophysical parameters of the target rock, the irreducible water saturation of the irreducible water in the target rock is predicted, and according to the irreducible water saturation, the isolated porosity of the target rock is obtained;

[0008] Based on the isolated porosity, the rock matrix modulus is adjusted, and based on the adjusted matrix modulus obtained after the adjustment, a rock physics model of the target rock is established.

[0009] According to another aspect of the present invention, a rock physics modeling device is provided, which may include:

[0010] A rock matrix modulus determination module is used to determine the rock matrix modulus of the target rock to be subjected to rock physics modeling;

[0011] An isolated porosity obtaining module is used to predict the irreducible water saturation of irreducible water in the target rock according to the rock physical parameters of the target rock, and obtain the isolated porosity of the target rock according to the irreducible water saturation;

[0012] The rock physics modeling module is used to adjust the rock matrix modulus based on the isolated porosity, and to establish a rock physics model of the target rock based on the adjusted matrix modulus obtained after the adjustment.

[0013] According to another aspect of the present invention, there is provided an electronic device, which may include:

[0014] at least one processor; and

[0015] a memory communicatively connected to at least one processor; wherein,

[0016] The memory stores a computer program that can be executed by at least one processor. The computer program is 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.

[0017] 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.

[0018] The technical solution in the embodiment of the present invention is for the target rock to be subjected to rock physics modeling, by determining the rock matrix modulus of the target rock, and predicting the bound water saturation of bound water in the target rock according to the rock physical parameters of the target rock, and obtaining the isolated porosity of the target rock according to the bound water saturation; further, based on the isolated porosity, the rock matrix modulus is adjusted, thereby adding bound water to the rock matrix, and then based on the adjusted matrix modulus obtained after the adjustment, a rock physics model is established for the target rock. The above technical solution, in the process of rock physics modeling, can effectively improve the accuracy of the rock physics model established thereby in characterizing the rock elastic parameters by considering the influence of complex pore connectivity and bound water saturation on the rock elastic parameters.

[0019] 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

[0020] 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.

[0021] Figure 1 is a flow chart of a rock physics modeling method provided according to an embodiment of the present invention;

[0022] Figure 2 is a flow chart of another rock physics modeling method provided according to an embodiment of the present invention;

[0023] Figure 3 is a flow chart of another rock physics modeling method provided according to an embodiment of the present invention;

[0024] Figure 4 is a flow chart of an optional example of another rock physics modeling method provided in an embodiment of the present invention;

[0025] Figure 5a is a schematic diagram of a first result of a first experimental example in another rock physics modeling method provided by an embodiment of the present invention;

[0026] Figure 5b is a schematic diagram of a second result of a first experimental example in another rock physics modeling method provided by an embodiment of the present invention;

[0027] Figure 6a is a schematic diagram of a first result of a second experimental example in another rock physics modeling method provided by an embodiment of the present invention;

[0028] Figure 6b is a schematic diagram of a second result of a second experimental example in yet another rock physics modeling method provided by an embodiment of the present invention;

[0029] Figure 7 is a structural block diagram of a rock physics modeling device provided according to an embodiment of the present invention;

[0030] Figure 8 It 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

[0031] 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.

[0032] 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.

[0033] Before introducing the embodiments of the present invention, the currently used rock physics modeling scheme and the application scenarios of the embodiments of the present invention are exemplified to better understand why the embodiments of the present invention can establish a rock physics model that can accurately predict rock elastic parameters.

[0034] Seismic rock physics is a bridge between rock physical parameters (such as reservoir lithology, porosity, pore pressure, permeability, fluid properties and fluid saturation, etc.) and rock elastic parameters (such as seismic wave velocity and attenuation, etc.), reflecting the relationship between the elastic properties of the rock itself and various physical properties. In other words, the elastic properties of reservoir rocks are closely related to their constituent minerals, grain size, porosity, pore structure, saturation and permeability.

[0035] On this basis, rock physics modeling establishes the correspondence between rock physical properties and rock elastic parameters through mathematical relationships. That is, the rock physics model constructed based on the equivalent medium theory can realize the mutual derivation between rock elastic parameters and rock physical properties, and can then be used to quantitatively analyze the impact of changes in rock physical properties on rock elastic parameters.

[0036] Furthermore, in the field of oil and gas reservoir exploration, with the continuous deepening of oil and gas resource exploration and development, the exploration targets are becoming more and more complex. Nowadays, in the study of reservoirs enriched with oil and gas resources and the prediction of fluid reservoirs, unconventional reservoir rocks with bound water are often the focus and difficulty of research. Deep and unconventional reservoirs are very rich in oil and gas resources, but it is difficult to quantitatively characterize geophysical data. The bound water saturation is one of the important parameters for evaluating multiphase flow and characterizing reservoir physical properties. The accuracy of bound water saturation calculation directly affects the accuracy of reservoir evaluation. However, it has been found that the various rock physics models currently proposed are used to predict the relationship between the free water saturation of reservoir rocks and the pore shape and rock elastic parameters, and the influence of complex pore connectivity and bound water saturation on rock elastic parameters is not taken into account, that is, it is not taken into account that there are usually connected pores and isolated pores in reservoir rocks, or there are free flowing free water and non-free flowing bound water at the same time. It can be seen that the currently established rock physics model cannot accurately predict the rock elastic parameters of reservoir rocks containing bound water, and needs to be improved.

[0037] 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 the case where irreducible water saturation is considered in the rock physics modeling process. The method can be executed by a rock physics modeling device provided by an embodiment of the present invention, and the device can be implemented by software and / or hardware, and the device can be integrated in an electronic device, and the electronic device can be various user terminals or servers.

[0038] See also Figure 1 The method of the embodiment of the present invention specifically includes the following steps:

[0039] S110. For the target rock to be subjected to rock physics modeling, determine the rock matrix modulus of the target rock.

[0040] The target rock may be understood as the rock for which rock physics modeling is to be performed, that is, the rock physics model of the target rock is to be established in the embodiment of the present invention.

[0041] The rock matrix modulus of the target rock is determined. In practical applications, optionally, the rock matrix modulus may be the bulk modulus and / or shear modulus of the rock matrix corresponding to the target rock.

[0042] S120. Predict the irreducible water saturation of irreducible water in the target rock based on the petrophysical parameters of the target rock, and obtain the isolated porosity of the target rock based on the irreducible water saturation.

[0043] Among them, the rock physical parameters can be understood as the physical parameters of the target rock, for example, at least one of the following: shale content, porosity, pore structure, and permeability. Immune water can be understood as the immobile water in isolated pores (i.e., unconnected pores) in the target rock. Immune water saturation can be understood as the saturation of irreducible water. On this basis, irreducible water saturation is predicted according to the rock physical parameters.

[0044] Furthermore, the isolated porosity of the target rock is obtained based on the irreducible water saturation.

[0045] S130. Adjust the rock matrix modulus based on the isolated porosity, and establish a rock physics model of the target rock based on the adjusted matrix modulus obtained after the adjustment.

[0046] The rock matrix modulus is adjusted based on the isolated porosity, thereby adding irreducible water to the rock matrix to obtain an adjusted matrix modulus. In practical applications, the irreducible water, specifically the isolated pores containing irreducible water, can be optionally added to the rock matrix through a self-consistent approximation (SCA) model.

[0047] Furthermore, based on adjusting the matrix modulus, a rock physics model of the target rock is established.

[0048] The technical solution in the embodiment of the present invention is for the target rock to be subjected to rock physics modeling, by determining the rock matrix modulus of the target rock, and predicting the bound water saturation of bound water in the target rock according to the rock physical parameters of the target rock, and obtaining the isolated porosity of the target rock according to the bound water saturation; further, based on the isolated porosity, the rock matrix modulus is adjusted, thereby adding bound water to the rock matrix, and then based on the adjusted matrix modulus obtained after the adjustment, a rock physics model is established for the target rock. The above technical solution, in the process of rock physics modeling, can effectively improve the accuracy of the rock physics model established thereby in characterizing the rock elastic parameters by considering the influence of complex pore connectivity and bound water saturation on the rock elastic parameters.

[0049] On this basis, an optional technical solution is to establish a rock physics model of the target rock based on the adjusted matrix modulus obtained after the adjustment, including:

[0050] Obtaining the adjusted matrix modulus obtained after adjustment, and calculating the dry rock skeleton modulus corresponding to the target rock according to the adjusted matrix modulus;

[0051] determining a mixed fluid modulus of a mixed fluid contained in pores within a target rock;

[0052] A rock physics model of the target rock is constructed based on the dry rock skeleton modulus, mixed fluid modulus and adjusted matrix modulus.

[0053] In practical applications, optionally, the dry rock skeleton modulus can be understood as the modulus of the dry rock skeleton corresponding to the target rock, for example, it can be the bulk modulus and / or shear modulus of the dry rock skeleton. Optionally, the KT model can be used to add the remaining pores to the rock matrix to which the isolated pores have been added, so as to obtain the dry rock skeleton; and more optionally, the magnetotelluric (MT) model can be used to calculate the dry rock skeleton modulus.

[0054] The mixed fluid can be understood as free water and fluid contained in the pores of the target rock, and the mixed fluid modulus can be understood as the elastic modulus of the mixed fluid. To determine the mixed fluid modulus, in practical applications, the mixed fluid modulus can be optionally calculated using the Brie formula.

[0055] Furthermore, in the process of constructing the rock physics model, the dry rock skeleton modulus, the mixed fluid modulus and the adjusted matrix modulus are considered at the same time. In this way, not only the factor of bound water saturation is considered, but also the mixed fluid is introduced into the dry rock skeleton, thereby better simulating the internal structure of the rock in the actual formation environment, thereby further improving the accuracy of the rock physics model for the characterization of rock elastic parameters. In practical applications, the mixed fluid can be introduced into the dry rock skeleton optionally using the Gassmann equation.

[0056] Another optional technical solution, the above-mentioned determination of the rock matrix modulus of the target rock includes:

[0057] Obtaining the particle modulus corresponding to at least one rock particle constituting the target rock, and the proportion of each rock particle of the at least one rock particle in the target rock;

[0058] For the rock matrix modulus to be determined of the target rock, the upper and lower limits of the rock matrix modulus are determined according to the particle modulus and proportion corresponding to at least one rock particle, and the rock matrix modulus is determined according to the upper and lower limits.

[0059] In practical applications, optionally, the upper and lower limits of the rock matrix modulus can be obtained by the Voigt and Reuss method, and then the rock matrix modulus can be obtained by averaging the upper and lower limits.

[0060] The above technical solution realizes the accurate calculation of the rock matrix modulus, that is, the mixture modulus of a rock particle mixture composed of at least one rock particle.

[0061] In order to better understand the following embodiments, before elaborating on them in detail, the research and development ideas are first exemplified. Exemplarily, it is found that nowadays, most of the prediction schemes of irreducible water saturation are based on nuclear magnetic resonance logging, but this scheme is difficult to combine irreducible water saturation with seismic rock physics, so that the relationship between irreducible water saturation and rock elastic parameters cannot be accurately established. On this basis, further research has found that irreducible water saturation is affected by many factors, especially closely related to factors such as mud content, porosity, pore structure and permeability. Therefore, the following embodiments give the relationship between rock reservoir parameters (such as porosity, permeability and mud content, etc.) and irreducible water, and then, in the case of considering the influence of irreducible water, the rock elastic properties are connected with the rock reservoir parameters, thereby filling the defects of the existing rock physics model that does not consider pore connectivity and irreducible water saturation.

[0062] Figure 2 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-mentioned technical solutions. In this embodiment, optionally, predicting the bound water saturation of bound water in the target rock according to the rock physical parameters of the target rock may include: obtaining the rock physical parameters of the target rock, and a bound water saturation prediction formula, wherein the rock physical parameters include at least one of permeability, porosity and mud content; using the bound water saturation prediction formula, predicting the bound water saturation of bound water in the target rock according to at least one of permeability, porosity and mud content. Among them, the explanations of the terms that are the same or corresponding to the above-mentioned embodiments are not repeated here.

[0063] See also Figure 2 The method of this embodiment may specifically include the following steps:

[0064] S210. For the target rock to be subjected to rock physics modeling, determine the rock matrix modulus of the target rock.

[0065] S220. Obtain rock physical parameters of the target rock and a prediction formula for irreducible water saturation, wherein the rock physical parameters include at least one of permeability, porosity, and shale content.

[0066] The rock physical parameter may be at least one of permeability, porosity and shale content that may affect irreducible water saturation. The irreducible water saturation prediction formula may be understood as a formula for predicting irreducible water saturation by using the rock physical parameter.

[0067] Obtain rock physical parameters and irreducible water saturation prediction formula.

[0068] S230. Predict the irreducible water saturation of irreducible water in the target rock according to at least one of the permeability, porosity and shale content using the irreducible water saturation prediction formula.

[0069] At least one of the permeability, porosity and shale content may be introduced into the irreducible water saturation prediction formula, so that the irreducible water saturation may be predicted using the irreducible water saturation prediction formula.

[0070] S240. Obtain the isolated porosity of the target rock according to the irreducible water saturation, and adjust the rock matrix modulus based on the isolated porosity to obtain an adjusted matrix modulus.

[0071] S250. Based on the adjusted matrix modulus, a rock physics model of the target rock is established.

[0072] The technical solution of the embodiment of the present invention realizes accurate prediction of irreducible water saturation by utilizing the irreducible water saturation prediction formula in combination with rock physical parameters that may affect the irreducible water saturation.

[0073] On this basis, an optional technical solution is that the number of irreducible water saturation prediction formulas is at least two, and the irreducible water saturation of irreducible water in the target rock is predicted based on at least one of permeability, porosity and shale content using the irreducible water saturation prediction formula, including:

[0074] Obtaining a preset permeability threshold, and determining a target prediction formula from at least two irreducible water saturation prediction formulas according to a numerical relationship between the permeability and the permeability threshold;

[0075] The target prediction formula is used to predict the irreducible water saturation of irreducible water in the target rock according to at least one of the permeability, the porosity and the shale content.

[0076] In practical applications, there are at least two irreducible water saturation prediction formulas, and different irreducible water saturation prediction formulas can be applied to permeabilities in different situations. The permeability threshold can be understood as a pre-set threshold related to the permeability. Obtain the permeability threshold.

[0077] According to the numerical relationship between the permeability and the permeability threshold, the target prediction formula for final application is determined from at least two irreducible water saturation prediction formulas. In practical applications, the numerical relationship may optionally reflect the magnitude relationship or multiple relationship between the permeability and the permeability threshold, which is not specifically limited here.

[0078] Furthermore, the irreducible water saturation is predicted according to at least one of the permeability, the porosity and the shale content by using the target prediction formula.

[0079] The above technical solution sets different irreducible water saturation prediction formulas for permeabilities in different situations, so that the irreducible water saturation prediction formula that matches the permeability can be used for prediction, thereby achieving accurate prediction of irreducible water saturation.

[0080] Figure 3 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, adjusting the rock matrix modulus based on isolated porosity may include: determining a geometric shape factor corresponding to the geometric shape of the pores in the target rock; adjusting the rock matrix modulus according to the geometric shape factor and the isolated porosity. Among them, the explanations of the terms that are the same or corresponding to the above embodiments are not repeated here.

[0081] See also Figure 3 The method of this embodiment may specifically include the following steps:

[0082] S310. For the target rock to be subjected to rock physics modeling, determine the rock matrix modulus of the target rock.

[0083] S320. Predict the irreducible water saturation of irreducible water in the target rock based on the rock physical parameters of the target rock, and obtain the isolated porosity of the target rock based on the irreducible water saturation.

[0084] S330. Determine a geometric shape factor corresponding to the geometry of the pores within the target rock.

[0085] The geometric shape may be used to describe the appearance of the pores in the target rock, for example, it may be coin-shaped, disk-shaped, needle-shaped or spherical, etc. This depends on the actual situation and is not specifically limited here.

[0086] The geometric shape factor can be understood as a factor corresponding to a geometric shape. Usually, different geometric shapes correspond to different geometric shape factors, which helps to consider the influence of different geometric shapes on rock elastic parameters in the rock physics modeling process.

[0087] S340. Adjust the rock matrix modulus according to the geometric shape factor and the isolated porosity, and establish a rock physics model of the target rock based on the adjusted matrix modulus obtained after the adjustment.

[0088] The rock matrix modulus is adjusted according to the geometric shape factor and the isolated porosity, so that a rock physics model can be established based on the adjusted matrix modulus.

[0089] The technical solution in the embodiment of the present invention, during the rock physics modeling process, takes into account the influence of different geometric shapes on rock elastic parameters, which makes the resulting rock physics model more consistent with the actual situation, thereby further improving the accuracy of rock elastic parameter characterization.

[0090] On this basis, an optional technical solution, the above-mentioned adjustment of the rock matrix modulus according to the geometric shape factor and the isolated porosity, may include: obtaining the water modulus, and adjusting the rock matrix modulus according to the geometric shape factor, the isolated porosity and the water modulus.

[0091] In other words, in addition to the geometry and bound water saturation, the water modulus is also taken into account during rock physics modeling, which makes the resulting rock physics model more consistent with the actual situation, thereby further improving the accuracy of rock elastic parameter characterization.

[0092] In order to better understand the above-mentioned technical solutions as a whole, the following is an exemplary description of the above-mentioned technical solutions in combination with specific examples. Figure 4 As shown in the figure, this example introduces a new equivalent medium theory, which is a rock physics model obtained by simulating the different porosity and pore structure of porous rocks. Specifically, for the target rock to be subjected to rock physics modeling, the rock matrix modulus of the target rock, that is, the bulk modulus and shear modulus of the rock matrix corresponding to the target rock, are calculated by the VRH average theory based on the particle modulus and proportion of various rock particles constituting the target rock. Then, based on the known rock physical parameters of the target rock and the bound water saturation prediction formula, the bound water saturation of the bound water in the target rock is obtained, and then the isolated pores containing bound water are added to the rock matrix through the SCA model, and the remaining pores are further added to the rock matrix using the KT model to obtain the dry rock skeleton corresponding to the target rock. Then, the mixed fluid modulus (that is, the elastic modulus of the mixed fluid) is calculated using the Brie formula, and the mixed fluid is further introduced into the dry rock skeleton using the Gassmann equation to simulate the internal structure of the target rock under the actual formation environment.

[0093] On this basis, in order to understand the above example more vividly, the following is an exemplary explanation in combination with a specific formula. For example, based on known rock physical parameters, the following irreducible water saturation prediction formula (1) or (2) is used to obtain irreducible water saturation:

[0094]

[0095]

[0096] Among them, H wi is the bound water saturation, %; E is the permeability, ×10-3 μm; is the porosity, a decimal; F sh is the mud content, a decimal. In practical applications, formula (1) can be applied to high permeability cases where E is greater than 10 mD, and formula (2) can be applied to low permeability cases where E is less than 10 mD.

[0097] In getting H wi Then, the isolated porosity of the target rock can be calculated using formula (3):

[0098]

[0099] The bulk modulus C of the rock matrix is ​​obtained m and shear modulus D m Afterwards, bound water can be added to the rock matrix through the SCA model (i.e., the following formulas (4) and (5):

[0100]

[0101]

[0102] Among them, C w is the bulk modulus of water; D w is the shear modulus of water; is the bulk modulus of the rock matrix after adding bound water; is the shear modulus of the rock matrix after adding bound water; M *i For calculation Geometric factor applied in the process; N *i For calculation The geometric shape factor applied in the process.

[0103] On this basis, several geometric shape factors are listed here, as follows:

[0104] Geometric shape factor M of coin-shaped pores *i and N *i The calculation formula is as follows:

[0105]

[0106]

[0107] Where α is the aspect ratio of the isolated pore, C i represents the bulk modulus of the i-th filler in the rock matrix, D i represents the shear modulus of the i-th filler, where the i-th filler can be bound water.

[0108] Geometric shape factor M of disk-like pores *i and N *i The calculation formula is as follows:

[0109]

[0110]

[0111] The geometric shape factor M of the needle-like pores *i and N *i The calculation formula is as follows:

[0112]

[0113]

[0114] The geometric shape factor M of the spherical pore *i and N *i The calculation formula is as follows:

[0115]

[0116]

[0117] in,

[0118]

[0119]

[0120]

[0121] In getting and Then, the bulk modulus of the dry rock skeleton can be calculated using the MT model (i.e., equations (6) and (7)): and shear modulus

[0122]

[0123]

[0124] Among them, M mi and N mi are the geometric shape factors of the i-th filling in the rock matrix (the calculation formula has been given above), where the i-th filling can be air; φ i is the porosity of the i-th filler, where the i-th filler can be air.

[0125] The elastic modulus of the mixed fluid in the pore (i.e., the bulk modulus C f and shear modulus D f) can be calculated by Brie formula (i.e., formula (8) and formula (9)):

[0126]

[0127] D f =0 (9)

[0128] Among them, C w is the bulk modulus of water; C g is the bulk modulus of the gas; S w is the water saturation. Generally, the exponent e reflects the distribution characteristics of the mixed fluid. In practical applications, it can be taken as [1,42], where a low value of e represents a patchy saturated distribution and a high value of e represents a uniform saturated distribution.

[0129] Finally, the Gassmann equation (i.e., equations (10) and (11)) can be used to add free water and gas (i.e., mixed fluid) to dry rock to obtain the bulk modulus C of the saturated rock: sat and D sat Shear modulus:

[0130]

[0131]

[0132] At this point, the rock physics model is completed.

[0133] The above example fully considers the influence of pore connectivity and irreducible water saturation on rock elastic parameters, and establishes a "double water" rock physics model containing free water and irreducible water in a complex pore structure based on the equivalent medium theory. Experiments have shown that compared with existing rock physics models, the rock physics model constructed in this example can more realistically simulate the internal structure and fluid distribution characteristics of underground rock formations, thereby more accurately predicting the rock elastic parameters of fluid-containing rocks, which has very important research and application value for actual exploration and development projects such as reservoir research on rich oil and gas resources and prediction of fluid reservoirs.

[0134] On this basis, in order to fully discuss the influence of different pore shapes on rock elastic parameters and verify the effectiveness of the "double water" rock physics model, a specific experimental example is given below. For example, carbonate rocks composed of quartz, calcite, dolomite and clay minerals are taken as an example, see Figure 5a and Figure 5b, which shows the changes in bulk modulus and shear modulus of carbonate rocks with and without bound water with porosity at different shale contents. As can be seen from the figure, the porosity of carbonate rocks has a great influence on the elastic modulus of rocks. With the increase of porosity, the P- and S-wave velocities of carbonate rocks decrease greatly, and the higher the shale content, the lower the P- and S-wave velocities. Assuming that the saturation or total saturation of carbonate rocks is the same, under the same shale content and porosity, the P- and S-wave velocities of carbonate rocks with bound water are higher than those of carbonate rocks without bound water.

[0135] Figure 6a The variation of the P- and S-wave velocities of carbonate rocks corresponding to the bulk modulus with irreducible water saturation under different shale contents and porosities is shown; similarly, Figure 6b The display shows the change of the P-wave and S-wave velocities corresponding to the shear modulus of carbonate rocks with irreducible water saturation under different shale contents and porosities. As can be seen from the figure, when the rock is saturated with water, regardless of how the shale content and porosity change, the P-wave and S-wave velocities increase with the increase of irreducible water saturation.

[0136] Figure 7 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. Figure 7 The device may specifically include: a rock matrix modulus determination module 410, an isolated porosity acquisition module 420 and a rock physics modeling module 430.

[0137] The rock matrix modulus determination module 410 is used to determine the rock matrix modulus of the target rock to be subjected to rock physics modeling;

[0138] An isolated porosity obtaining module 420 is used to predict the irreducible water saturation of irreducible water in the target rock according to the petrophysical parameters of the target rock, and obtain the isolated porosity of the target rock according to the irreducible water saturation;

[0139] The rock physics modeling module 430 is used to adjust the rock matrix modulus based on the isolated porosity, and to establish a rock physics model of the target rock based on the adjusted matrix modulus obtained after the adjustment.

[0140] Optionally, the isolated porosity obtaining module 420 may include:

[0141] A rock property parameter submodule, used to obtain the rock property parameters of the target rock and the irreducible water saturation prediction formula, wherein the rock property parameters include at least one of permeability, porosity and shale content;

[0142] The irreducible water saturation prediction submodule is used to predict the irreducible water saturation of irreducible water in the target rock according to at least one of permeability, porosity and shale content by using the irreducible water saturation prediction formula.

[0143] On this basis, optionally, the number of irreducible water saturation prediction formulas is at least two, and the irreducible water saturation prediction submodule includes:

[0144] a target prediction formula determination unit, configured to obtain a preset permeability threshold value, and determine a target prediction formula from at least two irreducible water saturation prediction formulas according to a numerical relationship between the permeability and the permeability threshold value;

[0145] The irreducible water saturation prediction unit is used to predict the irreducible water saturation of irreducible water in the target rock according to at least one of permeability, porosity and shale content by using a target prediction formula.

[0146] Optionally, the rock physics modeling module 430 includes:

[0147] a geometric shape factor determination submodule, for determining a geometric shape factor corresponding to the geometric shape of the pores in the target rock;

[0148] The rock matrix modulus adjustment submodule is used to adjust the rock matrix modulus according to the geometric shape factor and isolated porosity.

[0149] On this basis, optionally, the geometric shape factor determines the submodule, including:

[0150] The geometric shape factor determination unit is used to obtain the water modulus and adjust the rock matrix modulus according to the geometric shape factor, the isolated porosity and the water modulus.

[0151] Optionally, the rock physics modeling module 430 includes:

[0152] A dry rock skeleton modulus calculation unit is used to obtain the adjusted matrix modulus obtained after adjustment, and calculate the dry rock skeleton modulus corresponding to the target rock according to the adjusted matrix modulus;

[0153] a mixed fluid modulus determination unit, for determining the mixed fluid modulus of the mixed fluid contained in the pores within the target rock;

[0154] The rock physics modeling unit is used to construct a rock physics model of the target rock according to the dry rock skeleton modulus, the mixed fluid modulus and the adjusted matrix modulus.

[0155] Optionally, the rock matrix modulus determination module 410 includes:

[0156] A proportion acquisition unit, used to acquire the particle modulus corresponding to at least one rock particle constituting the target rock, and the proportion of each rock particle of the at least one rock particle in the target rock;

[0157] The rock matrix modulus determination unit is used to determine the upper and lower limits of the rock matrix modulus to be determined for the target rock according to the particle modulus and proportion corresponding to at least one rock particle, and determine the rock matrix modulus according to the upper and lower limits.

[0158] The rock physics modeling device provided in the embodiment of the present invention cooperates with the rock matrix modulus determination module and the isolated porosity acquisition module. For the target rock to be subjected to rock physics modeling, the rock matrix modulus of the target rock is determined, and the irreducible water saturation of irreducible water in the target rock is predicted according to the rock physical property parameters of the target rock, and the isolated porosity of the target rock is obtained according to the irreducible water saturation; further, the rock matrix modulus is adjusted based on the isolated porosity through the rock physics modeling module, thereby adding irreducible water to the rock matrix, and then a rock physics model is established for the target rock based on the adjusted matrix modulus obtained after the adjustment. The above-mentioned device can effectively improve the accuracy of the rock physics model established thereby in characterizing the rock elastic parameters by considering the influence of complex pore connectivity and irreducible water saturation on the rock elastic parameters during the rock physics modeling process.

[0159] The technical solution in the embodiment of the present invention is for the target rock to be subjected to rock physics modeling, by determining the rock matrix modulus of the target rock, and predicting the bound water saturation of bound water in the target rock according to the rock physical parameters of the target rock, and obtaining the isolated porosity of the target rock according to the bound water saturation; further, based on the isolated porosity, the rock matrix modulus is adjusted, thereby adding bound water to the rock matrix, and then based on the adjusted matrix modulus obtained after the adjustment, a rock physics model is established for the target rock. The above technical solution, in the process of rock physics modeling, can effectively improve the accuracy of the rock physics model established thereby in characterizing the rock elastic parameters by considering the influence of complex pore connectivity and bound water saturation on the rock elastic parameters.

[0160] 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.

[0161] 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.

[0162] Figure 8 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.

[0163] like Figure 8 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.

[0164] 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.

[0165] 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.

[0166] 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).

[0167] 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.

[0168] 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.

[0169] 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.

[0170] 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).

[0171] 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.

[0172] 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.

[0173] 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.

[0174] 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 rock matrix modulus of the target rock; Predicting the irreducible water saturation of irreducible water in the target rock according to the petrophysical parameters of the target rock, and obtaining the isolated porosity of the target rock according to the irreducible water saturation; Based on the isolated porosity, the rock matrix modulus is adjusted, and based on the adjusted matrix modulus obtained after the adjustment, a rock physics model of the target rock is established.

2. The method according to claim 1, characterized in that The step of predicting the irreducible water saturation of irreducible water in the target rock according to the petrophysical parameters of the target rock comprises: Obtaining rock physical parameters of the target rock and a prediction formula for irreducible water saturation, wherein the rock physical parameters include at least one of permeability, porosity, and shale content; The irreducible water saturation prediction formula is used to predict the irreducible water saturation of irreducible water in the target rock according to at least one of the permeability, the porosity and the shale content.

3. The method according to claim 2, characterized in that The number of the irreducible water saturation prediction formulas is at least two; The method of using the irreducible water saturation prediction formula to predict the irreducible water saturation of irreducible water in the target rock according to at least one of the permeability, the porosity, and the shale content includes: Acquiring a preset permeability threshold, and determining a target prediction formula from the at least two irreducible water saturation prediction formulas according to a numerical relationship between the permeability and the permeability threshold; The target prediction formula is used to predict the irreducible water saturation of irreducible water in the target rock according to at least one of the permeability, the porosity and the shale content.

4. The method according to claim 1, characterized in that: The adjusting the rock matrix modulus based on the isolated porosity comprises: determining a geometric shape factor corresponding to the geometry of pores within the target rock; The rock matrix modulus is adjusted based on the geometric shape factor and the isolated porosity.

5. The method according to claim 4, characterized in that The step of adjusting the rock matrix modulus according to the geometric shape factor and the isolated porosity comprises: A water modulus is obtained, and the rock matrix modulus is adjusted based on the geometric shape factor, the isolated porosity, and the water modulus.

6. The method according to claim 1, characterized in that The step of establishing a rock physics model of the target rock based on the adjusted matrix modulus obtained after the adjustment includes: Obtaining the adjusted matrix modulus obtained after adjustment, and calculating the dry rock skeleton modulus corresponding to the target rock according to the adjusted matrix modulus; determining a mixed fluid modulus of a mixed fluid contained in pores within the target rock; A rock physics model of the target rock is constructed according to the dry rock skeleton modulus, the mixed fluid modulus and the adjusted matrix modulus.

7. The method according to claim 1, characterized in that Determining the rock matrix modulus of the target rock includes: Obtaining the particle modulus corresponding to at least one rock particle constituting the target rock, and the proportion of each rock particle in the at least one rock particle in the target rock; For the rock matrix modulus to be determined of the target rock, the upper limit and lower limit of the rock matrix modulus are determined according to the particle modulus and proportion corresponding to the at least one rock particle, and the rock matrix modulus is determined according to the upper limit and the lower limit.

8. A rock physics modeling device, characterized in that: include: A rock matrix modulus determination module, for determining the rock matrix modulus of a target rock to be subjected to rock physics modeling; An isolated porosity obtaining module is used to predict the irreducible water saturation of irreducible water in the target rock according to the petrophysical parameters of the target rock, and obtain the isolated porosity of the target rock according to the irreducible water saturation; The rock physics modeling module is used to adjust the rock matrix modulus based on the isolated porosity, and to establish a rock physics model of the target rock based on the adjusted matrix modulus obtained after the adjustment.

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.

Images