Method and device for constructing poroperm relationship of heterogeneous reservoir, equipment and storage medium

Abstract

The application belongs to the technical field of oil and gas reservoir prediction, and discloses a method for constructing the pore-permeability relationship of a heterogeneous reservoir, which respectively calculates the connected pore volume percentage, the equivalent structural parameter of the connected pores, and the permeability of the connected pores, divides the reservoir type through the equivalent structural parameter gamma of the connected pores, defines the reservoir sample as type I pores when gamma is greater than 0.005, and defines the reservoir sample as type II pores when gamma is less than or equal to 0.005; respectively establishes the pore-permeability relationship between the connected pore volume percentage alpha and the absolute permeability k of the connected pore space of the type I pore and type II pore samples, and realizes the construction of the pore-permeability relationship based on the equivalent structure of the connected pores; and the application further discloses a device and equipment for constructing the pore-permeability relationship of a heterogeneous reservoir and a storage medium. The application is used for finely constructing the pore-permeability relationship of a heterogeneous reservoir, providing a more reasonable pore-permeability relationship for the fine development of different types of reservoirs, and thus improving the prediction accuracy of the permeability of a heterogeneous reservoir.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of oil and gas reservoir prediction, and relates to a heterogeneous reservoir porosity-permeability relationship construction method, device, equipment and storage medium. BACKGROUND

[0002] The calculation of permeability plays a crucial role in the development of oil and gas reservoirs. Currently, the porosity-permeability relationship is mainly used to calculate the permeability on the basis of porosity inversion results. The accuracy of the porosity-permeability relationship affects the accuracy of the permeability prediction of oil and gas reservoirs, and is a key indicator for the prediction of high-quality reservoir sweet spots in the process of oil and gas exploration and development. Therefore, the construction of a fine porosity-permeability relationship plays a decisive role in the calculation of the permeability of oil and gas reservoirs and becomes a core factor affecting the development plan of oil and gas.

[0003] The internal space of rock pores in actual rock, especially in heterogeneous reservoirs, is extremely complex. The internal space characteristics of different types of reservoirs differ greatly. In particular, unconventional oil and gas reservoirs have the characteristics of strong heterogeneity, multi-scale pore space development, and large differences in pore structure characteristics, which leads to a very complex porosity-permeability relationship in the reservoir. In particular, in the case of similar porosity, the difference in pore structure can cause the difference in permeability of the reservoir to reach two orders of magnitude. If the difference in pore structure is not considered when establishing the porosity-permeability relationship, it will seriously restrict the accuracy of the prediction of reservoir sweet spots. Currently, in actual applications, rock physical experiments or logging data are usually used to obtain porosity and permeability parameters and construct the porosity-permeability relationship. However, the parameters obtained by these methods cannot be linked to the corresponding pore structure characteristics, and the influence of different pore structures in heterogeneous reservoirs on permeability cannot be distinguished. The porosity-permeability relationship constructed on this basis cannot reasonably describe the porosity-permeability relationship of heterogeneous reservoirs and cannot meet the permeability prediction needs of heterogeneous reservoirs with different pore structures.

[0004] Therefore, for complex oil and gas reservoirs with strong heterogeneity, it is urgent to develop a porosity-permeability relationship construction method that can fully consider the influence of differences in pore structure characteristics, finely characterize the differences in the internal porosity-permeability relationship of heterogeneous reservoirs, and provide a more reasonable and reliable model and basis for the calculation of the permeability of oil and gas reservoirs, so as to more accurately calculate the permeability of heterogeneous reservoirs on the basis of porosity data. SUMMARY

[0005] The purpose of the present application is to provide a heterogeneous reservoir porosity-permeability relationship construction method. By introducing digital rock physics technology, fine calculation is carried out on connected pores to obtain the connected pore volume percentage, the equivalent structure parameters of connected pores, and the permeability of connected pores. The type-specific construction of the porosity-permeability relationship is realized under the guidance of the equivalent structure parameters of connected pores, and a more fine porosity-permeability relationship of heterogeneous reservoirs is obtained.

[0006] Another object of the present application is to provide a heterogeneous reservoir porosity-permeability relationship construction device, equipment and storage medium, which can effectively improve the fineness of porosity-permeability relationship construction and provide a more reasonable basis for the calculation of heterogeneous reservoir permeability.

[0007] In order to achieve the above object, the technical scheme adopted by the present application is as follows:

[0008] A heterogeneous reservoir porosity-permeability relationship construction method, comprising the following steps:

[0009] S1, calculating the connected pore volume percentage

[0010] A three-dimensional core image of a target area reservoir is obtained, connected pore clusters in the three-dimensional core image are determined based on grid search, a connected pore space A is obtained according to the connected pore clusters, and the connected pore volume percentage a of the connected pore space A is calculated;

[0011] S2, calculating the equivalent structure parameters of the connected pores

[0012] A mathematical morphology dilation operation is performed on the connected pore space A using a structure element B to obtain a pore space C; the difference between the pore space C and the connected pore space A is calculated to obtain the surface pixel points of the connected pores, and the number N of the surface pixel points of the connected pores is counted Surface , to obtain the equivalent structure parameters y of the connected pores;

[0013] S3, calculating the permeability of the connected pores

[0014] According to the connected pore space A, the opposite two end faces of the core in the three-dimensional core image in the coordinate axis direction are respectively set as the fluid injection end and the outflow end, the pressure difference of the fluid injection end and the outflow end is set, the flow of single-phase fluid in the connected pore space A under the action of pressure gradient is simulated, and when the flow rate and flow reach stability, the absolute permeability k of the connected pore space is calculated;

[0015] S4, constructing the porosity-permeability relationship under the guidance of the equivalent structure of the connected pores by type

[0016] The reservoir type is divided through the equivalent structure parameters y of the connected pores, when the reservoir sample y>0.005, it is defined as type I pores, and when the reservoir sample y≤0.005, it is defined as type II pores; the least square fitting is used to respectively establish the porosity-permeability relationship between the connected pore volume percentage a and the absolute permeability k of the connected pore space of the type I pore and type II pore reservoir samples, and the porosity-permeability relationship construction based on the equivalent structure of the connected pores is realized.

[0017] As a limitation, in step S1, the connected pore clusters in the three-dimensional core image are determined based on a grid search, and the connected pore space A is obtained according to the connected pore clusters, and the specific process of calculating the connected pore volume percentage a of the connected pore space A is as follows:

[0018] Each pixel in the three-dimensional core image is set as a grid, and the state of the pixel located in the pore is set as "occupied", and the states of the remaining pixels are all set as "free";

[0019] If the edge of the pore pixel does not contact the pixel with the state of "occupied", the pore pixel is regarded as a new pore cluster, and a new pore cluster label is assigned;

[0020] If the edge of the pore pixel contacts the pixel with the state of "occupied", the pore pixel and the contacted "occupied" pixel are regarded as a pore cluster, and the same pore cluster label as the pore pixel is adopted; wherein the pore cluster label number is i (i = 1, 2, …, N), and N is the total number of pore clusters;

[0021] It is judged whether there is a pore cluster with the same pore cluster label on the opposite two end faces of the core in the coordinate axis direction of the three-dimensional core image, if there is, the pore cluster forms a fluid migration channel penetrating the core, and all pixel points belonging to the pore cluster belong to the connected pore cluster; if there are multiple connected pore clusters, all pixel points of the connected pore clusters belong to the connected pore space A;

[0022] The number N of all pixel points in the three-dimensional core image is counted Total , and the number N of all connected pore pixel points in the connected pore space A is counted Percolated , and the connected pore volume percentage a of the connected pore space is calculated;

[0023]

[0024] As a further limitation, in step S2, the structural element B is set as a sphere with a radius of 1;

[0025] The calculation formula of the pore space C is:

[0026]

[0027] wherein, is an empty set, the pore space C is the result of the connected pore space A being inflated by the structural element B, and is recorded as is an inflation operator, x is a translation distance, is the space obtained by translating the structural element B by x;

[0028] The calculation formula of the equivalent structural parameter y of the connected pore is:

[0029]

[0030] As a second limitation, in step S3, the lattice Boltzmann algorithm is used to simulate the flow of single-phase fluid in the connected pore space A under the action of pressure gradient;

[0031] The absolute permeability k of the connected pore space is calculated according to Darcy's law:

[0032]

[0033] Wherein, μ is the viscosity of the fluid, mPa·s; ΔP is the pressure difference between the fluid injection end and the flow-out end, MPa; Q is the flow rate through the core, cm 3 / s; S is the cross-sectional area of the core perpendicular to the coordinate axis of the core in the three-dimensional core image, cm 2 ; L is the length of the core in the direction of the coordinate axis of the core in the three-dimensional core image;

[0034]

[0035] The application also provides a heterogeneous reservoir porosity-permeability relationship construction device, comprising:

[0036] A connected pore volume percentage calculation module is configured to obtain a three-dimensional core image of a target area reservoir, determine connected pore clusters in the three-dimensional core image based on grid search, obtain a connected pore space A according to the connected pore clusters, and calculate a connected pore volume percentage α of the connected pore space A;

[0037] An equivalent structural parameter calculation module of the connected pores is configured to perform mathematical morphological dilation operation on the connected pore space A using a structural element B to obtain a pore space C; calculate the difference between the pore space C and the connected pore space A to obtain surface pixel points of the connected pores; and traverse and count the number N Surface of the surface pixel points of the connected pores to obtain the equivalent structural parameter γ of the connected pores;

[0038] A permeability calculation module of the connected pores is configured to set two opposite end faces of the core in the three-dimensional core image in the direction of the coordinate axis as a fluid injection end and a flow-out end respectively according to the connected pore space A, set the pressure difference between the fluid injection end and the flow-out end, simulate the flow of single-phase fluid in the connected pore space A under the action of pressure gradient, and calculate the absolute permeability k of the connected pore space when the flow rate and flow rate reach stability.

[0039] The pore-permeability relationship construction module is used for dividing the reservoir type through the equivalent structure parameter gamma of the connected pores, defining the reservoir sample as the first type of pores when gamma>0.005, and defining the reservoir sample as the second type of pores when gamma<=0.005; the pore-permeability relationship between the connected pore volume percentage alpha and the absolute permeability k of the connected pore space of the reservoir sample of the first type of pores and the second type of pores is respectively established by using the least square fitting, and the pore-permeability relationship construction based on the equivalent structure of the connected pores is realized.

[0040] The application further provides a computer device comprising a processor and a memory, wherein the memory is used for storing at least one piece of computer program, the at least one piece of computer program is loaded and executed by the processor, and the non-homogeneous reservoir pore-permeability relationship construction method is executed.

[0041] The application further provides a storage medium used for storing at least one piece of computer program, and the at least one piece of computer program is used for executing the non-homogeneous reservoir pore-permeability relationship construction method.

[0042] The application has the following technical progress compared with the prior art:

[0043] (1) The application introduces the digital rock physics technology to carry out fine calculation on the connected pores, obtains the connected pore volume percentage, the equivalent structure parameter of the connected pores and the permeability of the connected pores, and realizes the type-based construction of the pore-permeability relationship under the guidance of the equivalent structure parameter of the connected pores, thereby obtaining the more fine pore-permeability relationship of the non-homogeneous reservoir.

[0044] (2) The fine pore-permeability relationship correlation coefficients of the first type of pores and the second type of pores constructed based on the equivalent structure of the connected pores can reach 0.90 and 0.67 respectively, and compared with the pore-permeability relationship correlation of 0.45 established by not considering the pore structure, the application not only effectively distinguishes the difference of the characteristics of the non-homogeneous reservoir, but also greatly improves the accuracy of the pore-permeability relationship, thereby providing a more reasonable basis for the calculation of the permeability of the non-homogeneous reservoir.

[0045] In conclusion, the application is used for carrying out the fine construction of the pore-permeability relationship of the non-homogeneous reservoir, realizing the fine quantitative characterization of the complex pore-permeability relationship of the non-homogeneous reservoir, providing a more reasonable pore-permeability relationship for the fine development of different types of reservoirs, and thereby improving the prediction accuracy of the permeability of the non-homogeneous reservoir. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 Fig. 1 shows the method flowchart of the embodiment 1 of the application;

[0047] Fig. 2(a) shows the schematic diagram of the pixels of the three-dimensional core image in the embodiment 1 of the application;

[0048] Figure 2(b) shows a schematic diagram of the pore cluster marking in Embodiment 1 of the present invention;

[0049] Figure 3(a) shows a three-dimensional grayscale image of the core in the connected pore space A in Embodiment 1 of the present invention;

[0050] Figure 3(b) shows the connectivity analysis diagram of the connected pore space A in Embodiment 1 of the present invention;

[0051] Figure 4(a) shows a schematic diagram of the measurement of the surface area of ​​the connected pores in Embodiment 1 of the present invention;

[0052] Figure 4(b) shows a schematic diagram of the surface pixels of the connected aperture in Embodiment 1 of the present invention;

[0053] Figure 5 The diagram shown is a simulation of the flow velocity distribution in the connected pore space A in Embodiment 1 of the present invention;

[0054] Figure 6 The figure shown is a comparison diagram of the porosity-permeability relationship based on the equivalent structure of connected pores in Embodiment 1 of the present invention and the original result.

[0055] Figure 7 The diagram shown is a block diagram of the device according to Embodiment 2 of the present invention;

[0056] Figure 8 The diagram shown is a structural schematic of the computer device according to Embodiment 2 of the present invention;

[0057] Figure 9 The diagram shown is a structural schematic of the computer storage medium according to Embodiment 2 of the present invention. Detailed Implementation

[0058] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0059] Example 1: A method for constructing the porosity-permeability relationship in heterogeneous reservoirs

[0060] like Figure 1 As shown in the figure, this embodiment describes a method for constructing the porosity-permeability relationship of a heterogeneous reservoir, which includes the following steps:

[0061] S1. Calculate the percentage of connected pore volume.

[0062] Obtain three-dimensional core images of the reservoir in the target area, determine the connected pore clusters in the three-dimensional core images based on grid search, obtain the connected pore space A based on the connected pore clusters, and calculate the connected pore volume percentage α of the connected pore space A.

[0063] In this step, the connected pore clusters in the three-dimensional core image are determined based on grid search, and the connected pore space A is obtained according to the connected pore clusters. The specific process of calculating the connected pore volume percentage α of the connected pore space A is as follows:

[0064] As shown in Fig. 2(a), each pixel in the three-dimensional core image is set as a grid, and the state of the pixel located in the pore is set as "occupied" and recorded as a pore pixel, and the states of the remaining pixels are all set as "free";

[0065] If the edge of the pore pixel does not contact the pixel with the state of "occupied", the pore pixel is regarded as a new pore cluster, and a new pore cluster label is assigned to the pore pixel;

[0066] If the edge of the pore pixel contacts the pixel with the state of "occupied", the pore pixel and the contacted "occupied" pixel are regarded as a pore cluster, and the same pore cluster label as the pore pixel is adopted; wherein the pore cluster label number is i (i = 1, 2, …, N), and N is the total number of pore clusters;

[0067] As shown in Fig. 2(b), it is a schematic diagram of the pore cluster label. As can be seen from the figure, the pore cluster label number is 1-4, wherein the pore cluster label 1 is that the edge of the pore pixel contacts one pixel with the state of "occupied", so the pore pixel and the contacted "occupied" pixel are regarded as a pore cluster, and the pore cluster label 1 is used to represent; the pore cluster label 2 is that the edge of the pore pixel does not contact the pixel with the state of "occupied", so the pore pixel is regarded as a new pore cluster, and the pore cluster label 2 is used to represent, and the pore cluster label 3 and the pore cluster label 4 are the same;

[0068] It is judged whether there is a pore cluster with the same pore cluster label on the two end faces opposite to each other in the X-axis direction of the three-dimensional core image. If there is, the pore cluster forms a fluid migration channel penetrating through the core, and all the pixel points belonging to the pore cluster belong to the connected pore cluster; if there are multiple connected pore clusters, all the pixel points of the connected pore clusters belong to the connected pore space A;

[0069] As shown in Fig. 3(a), it is a three-dimensional gray scale image of the core in the obtained connected pore space A. The three-dimensional gray scale image of the core in the figure is the original image of the core, and the connected pore space in the figure is the connected pore space A;

[0070] As shown in Fig. 3(b), it is a connectedness analysis diagram of the connected pore space A. The green area in the figure is the connected pore space A, and the non-connected pore and the rock skeleton are set as transparent;

[0071] The number N of all the pixel points in the three-dimensional core image is counted Total , and the number N of all the connected pore pixel points in the connected pore space A is counted Percolated, the connected pore volume percentage a of the connected pore space is calculated;

[0072]

[0073] The size of the core in the three-dimensional core image taken in this step is 300*300*300, the number of all pixel points M in the three-dimensional core image Total = 27000000, the number of all connected pore pixel points N in the through pore space A Percolated = 2475630, so

[0074] S2, the equivalent structural parameters of the connected pores are calculated

[0075] The connected pore space A is subjected to mathematical morphological dilation operation using the structural element B, and the pore space C is obtained through the dilation operation;

[0076] In this step, the structural element B is set to a sphere with a radius of 1;

[0077] The calculation formula of the pore space C is:

[0078]

[0079] Among them, is an empty set, and the pore space C is the result of the dilation of the connected pore space A by the structural element B, denoted as is the dilation operator, x is the translation distance, is the space obtained by translating the structural element B by x; the dilation operation process described by the formula is that the structural element B is first mapped about its origin, and then translated by x; the dilation operation of the connected pore space A by the structural element B is translated by all x and has at least one non-zero common element with the connected pore space A;

[0080] The difference between the pore space C and the connected pore space A is calculated to obtain the surface pixel points of the connected pores. As shown in Fig. 4(a), it is a connected pore surface area measurement schematic diagram, and the circular shape in the figure is the pore space C obtained after the connected pore space A is subjected to the dilation operation by the structural element B. The difference between the pore space C and the connected pore space A is calculated to obtain the surface pixel points of the connected pores. As shown in Fig. 4(b), it is a connected pore surface pixel point schematic diagram. The number of surface pixel points of the connected pores is counted Surface , and the equivalent structural parameters y of the connected pores are obtained;

[0081] The calculation formula of the equivalent structural parameters y of the connected pores is:

[0082]

[0083] The number N of surface pixel points of the connected pore taken in this step Surface = 148537, so the equivalent structural parameters of the connected pore obtained

[0084] S3, calculating the permeability of the connected pore

[0085] According to the connected pore space A, the opposite two end faces of the core in the three-dimensional core image in the X-axis direction are respectively set as the fluid injection end and the fluid outlet end, the pressure difference of the fluid injection end and the fluid outlet end is set, and the lattice Boltzmann algorithm is used to simulate the flow of single-phase fluid in the connected pore space A under the action of the pressure gradient, i.e. the pressure difference of the fluid injection end and the fluid outlet end, as shown in Figure 5 The flow velocity distribution simulation diagram of the connected pore space A is shown in the figure, from which it can be seen that the fluid flows in from the left side along the X-axis direction and flows out from the right side, the curved flow lines in the figure represent the path of the fluid flow, and the color scale of the flow lines represents the velocity of the fluid;

[0086] When the flow velocity and flow rate reach stability, the absolute permeability k of the connected pore space is calculated according to Darcy's law;

[0087]

[0088] Wherein, μ is the viscosity of the fluid, mPa·s; ΔP is the pressure difference of the fluid injection end and the fluid outlet end, MPa; Q is the flow rate through the core, cm 3 / s; S is the cross-sectional area of the core perpendicular to the X-axis in the three-dimensional core image, cm 2 ; L is the length of the core in the X-axis direction in the three-dimensional core image;

[0089] When selecting the value of ΔP, since the equivalent structural parameter γ of the connected pore reflects the pore structure characteristics, the larger the value of γ, the larger the pore surface area and the more irregular the shape. In order to improve the efficiency of the lattice Boltzmann simulation calculation of the absolute permeability k of the connected pore space, different fluid injection end and fluid outlet end pressure differences ΔP are selected for different equivalent structural parameters γ of the connected pore to ensure that the samples with different pore structures can obtain reasonable absolute permeability k of the connected pore space:

[0090]

[0091] S4, constructing the pore permeability relationship under the guidance of the connected pore equivalent structure

[0092] The reservoir type is divided by the equivalent structure parameter γ of the connected pore, and when the reservoir sample γ>0.005, it is defined as the first type of pore, and when the reservoir sample γ≤0.005, it is defined as the second type of pore; the least square fitting is used to respectively establish the pore-permeability relationship between the connected pore volume percentage α and the absolute permeability k of the connected pore space of the first type of pore and the second type of pore reservoir sample, so as to realize the pore-permeability relationship construction based on the equivalent structure of the connected pore.

[0093] As shown in Figure 6 The comparison chart of the pore-permeability relationship based on the equivalent structure of the connected pore in the embodiment and the pore-permeability relationship established by the same sample data without considering the pore structure is shown in the figure; the upper chart is the pore-permeability relationship based on the equivalent structure of the connected pore in the embodiment, and the lower chart is the pore-permeability relationship established by the same sample data without considering the pore structure; as shown in the figure, the correlation coefficient of the fine pore-permeability relationship of the first type of pore constructed based on the equivalent structure of the connected pore is 0.44, the correlation coefficient of the fine pore-permeability relationship of the second type of pore can reach 0.90, the correlation of the pore-permeability relationship established by the same sample data without considering the pore structure is 0.45, which shows that the embodiment effectively distinguishes the difference of the heterogeneous reservoir characteristics and greatly improves the accuracy of the pore-permeability relationship, thereby providing a more reasonable basis for the calculation of the permeability of the heterogeneous reservoir.

[0094] Therefore, the embodiment realizes the fine quantitative characterization of the complex pore-permeability relationship of the heterogeneous reservoir, provides a more reasonable pore-permeability relationship for the fine development of different types of reservoirs, and thus improves the prediction accuracy of the permeability of the heterogeneous reservoir.

[0095] Embodiment 2: A heterogeneous reservoir pore-permeability relationship construction device, equipment and storage medium

[0096] As shown in Figure 7 The embodiment provides a heterogeneous reservoir pore-permeability relationship construction device, which comprises:

[0097] The connected pore volume percentage calculation module is used to obtain the three-dimensional core image of the target area reservoir, determine the connected pore cluster in the three-dimensional core image based on the grid search, obtain the connected pore space A according to the connected pore cluster, and calculate the connected pore volume percentage α of the connected pore space A;

[0098] The equivalent structure parameter calculation module of the connected pore is used to perform mathematical morphological dilation operation on the connected pore space A using the structure element B to obtain the pore space C; the difference between the pore space C and the connected pore space A is calculated to obtain the surface pixel points of the connected pore, and the number N of the surface pixel points of the connected pore is counted to obtain the equivalent structure parameter γ of the connected pore; Surface

[0099] ​The permeability calculation module of the connected pore is used for setting two opposite end faces of the core in the three-dimensional core image as a fluid injection end and a flow-out end respectively according to the connected pore space A, setting a pressure difference of the fluid injection end and the flow-out end, simulating the flow of the single-phase fluid in the connected pore space A under the action of the pressure gradient, and calculating the absolute permeability k of the connected pore space when the flow rate and the flow reach stability.

[0100] The pore-permeability relationship construction module is used for dividing the reservoir types through the equivalent structural parameter γ of the connected pore, defining the reservoir sample as a class I pore when γ>0.005, and defining the reservoir sample as a class II pore when γ≤0.005; and establishing the pore-permeability relationship between the connected pore volume percentage α and the absolute permeability k of the connected pore space of the class I pore and the class II pore reservoir sample respectively by least square fitting, so as to realize the pore-permeability relationship construction based on the equivalent structure of the connected pore.

[0101] In the data processing, only the division of the above functional modules is used as an example, and in actual application, the above functions can be completed by different functional modules according to needs.

[0102] Based on the same inventive concept, as shown in Figure 8 The embodiment further provides a computer device, which comprises at least a processor and a memory, the memory is used for storing at least one computer program, the at least one computer program is loaded and executed by the processor to implement the non-homogeneous reservoir pore-permeability relationship construction method of the embodiment 1.

[0103] Based on the same inventive concept, as shown in Figure 9 The embodiment further provides a computer readable storage medium, the storage medium is used for storing at least one computer program, and the at least one computer program is used for executing the non-homogeneous reservoir pore-permeability relationship construction method of the embodiment 1.

[0104] It should be noted that those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program to instruct related hardware, and the program can be stored in a computer readable storage medium, and the program can include the processes of the above-mentioned embodiments when executed.

[0105] In addition, it should be understood that the computer readable storage medium (for example, the memory) herein can be a volatile memory or a non-volatile memory, or can include both a volatile memory and a non-volatile memory.

[0106] Those skilled in the art will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the disclosure herein can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present embodiments.

[0107] It should be noted that the above-mentioned embodiments are only preferred embodiments of the present application, and are not used to limit the present application. Although the present application has been described in detail with reference to the above-mentioned embodiments, those skilled in the art can make modifications to the technical solutions recorded in the above-mentioned embodiments, or make equivalent replacements to some technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for constructing a poroperm relationship of a heterogeneous reservoir, characterized in that, The method comprises the following steps: S1, calculating the connected pore volume percentage Obtaining a three-dimensional core image of a target area reservoir, determining a connected pore cluster in the three-dimensional core image based on grid search, obtaining a connected pore space A according to the connected pore cluster, and calculating a connected pore volume percentage a of the connected pore space A; S2, calculating the equivalent structure parameter of the connected pore Using a structure element B to perform a mathematical morphological dilation operation on the connected pore space A to obtain a pore space C; The difference between the pore space C and the connected pore space A is calculated to obtain surface pixel points of the connected pore, and the number N of the surface pixel points of the connected pore is counted Surface to obtain the equivalent structural parameter γ of the connected pore S3, calculating the permeability of the connected pore According to the connected pore space A, the opposite two end faces of the core in the three-dimensional core image in the direction of the coordinate axis are respectively set as a fluid injection end and a flow-out end, a pressure difference of the fluid injection end and the flow-out end is set, the flow of a single-phase fluid in the connected pore space A under the action of a pressure gradient is simulated, and when the flow rate and flow reach stability, the absolute permeability k of the connected pore space is calculated; S4, constructing the pore permeability relationship under the guidance of the equivalent structure of the connected pore by type The reservoir type is divided by the equivalent structure parameter y of the connected pore, when the reservoir sample y>0.005, it is defined as type I pore, and when the reservoir sample y≤0.005, it is defined as type II pore; the pore permeability relationship between the connected pore volume percentage a and the absolute permeability k of the connected pore space of the type I pore and type II pore reservoir samples is respectively established by least square fitting, and the pore permeability relationship based on the equivalent structure of the connected pore is constructed.

2. The method of claim 1, wherein, In step S1, the connected pore cluster in the three-dimensional core image is determined based on grid search, the connected pore space A is obtained according to the connected pore cluster, and the specific process of calculating the connected pore volume percentage a of the connected pore space A is as follows: Each pixel in the three-dimensional core image is set as a grid, the state of the pixel located in the pore is set as "occupied", and the state of the remaining pixels is set as "free"; If the edge of the pore pixel does not contact the pixel with the state of "occupied", the pore pixel is regarded as a new pore cluster, and a new pore cluster label is assigned; If the edge of the pore pixel contacts the pixel with the state of "occupied", the pore pixel and the contacted "occupied" pixel are regarded as a pore cluster, and the same pore cluster label as the pore pixel is adopted; wherein, the pore cluster label number is i (i=1, 2, …, N), and N is the total number of pore clusters; It is judged whether there is a pore cluster with the same pore cluster label on the opposite two end faces of the core in the three-dimensional core image in the direction of the coordinate axis, if there is, the pore cluster forms a fluid migration channel penetrating through the core, and all pixel points belonging to the pore cluster belong to the connected pore cluster; if there are multiple connected pore clusters, all pixels of the connected pore clusters belong to the connected pore space A; Count all the pixel points in the statistical three-dimensional core image N Total , and count all the connected pore pixel points in the connected pore space A N Percolated , calculate the connected pore volume percentage α of the connected pore space; 3. The method of claim 2, wherein, In step S2, the structure element B is set as a sphere with a radius of 1; The calculation formula of the pore space C is: wherein, is the empty set, the pore space C is the result of the dilation of the connected pore space A by the structuring element B, denoted as is the dilation operator, x is the translation distance, is the space obtained by translating the structuring element B by x. The calculation formula of the equivalent structure parameter y of the connected pore is:

4. The method for constructing the porosity-permeability relationship of a heterogeneous reservoir according to claim 1, characterized in that, In step S2 and step S3, the lattice Boltzmann algorithm is used to simulate the flow of a single-phase fluid in the connected pore space A under the action of a pressure gradient; The absolute permeability k of the connected pore space is calculated according to Darcy's law: wherein μ is the viscosity of the fluid, mPa s; ΔP is the pressure difference between the fluid injection end and the fluid efflux end, MPa; Q is the flow rate through the core, cm 3 / s; S is the cross-sectional area of the core perpendicular to the coordinate axis in which the core is located in the three-dimensional core image, cm 2 ; L is the length of the core in the direction of the coordinate axis in which the core is located in the three-dimensional core image.

5. A device for constructing a poroperm relationship of a heterogeneous reservoir, characterized in that, It comprises: The connected pore volume percentage calculation module is configured to acquire a three-dimensional core image of a target area reservoir, determine connected pore clusters in the three-dimensional core image based on a grid search, obtain a connected pore space A according to the connected pore clusters, and calculate a connected pore volume percentage a of the connected pore space A; The connected pore equivalent structural parameter calculation module is configured to perform a mathematical morphology dilation operation on the connected pore space A using a structural element B to obtain a pore space C; The difference between the pore space C and the connected pore space A is calculated to obtain surface pixel points of the connected pore, and the number N of the surface pixel points of the connected pore is counted Surface to obtain the equivalent structural parameter γ of the connected pore. The connected pore permeability calculation module is configured to set two opposite end faces of a core in the three-dimensional core image as a fluid injection end and a flow-out end according to the connected pore space A, set a pressure difference between the fluid injection end and the flow-out end, simulate a single-phase fluid flow in the connected pore space A under the action of a pressure gradient, and calculate an absolute permeability k of the connected pore space when a flow rate and a flow volume reach a steady state. The pore-permeability relationship construction module is configured to divide reservoir types according to the connected pore equivalent structural parameter γ, define a reservoir sample as a Class I pore when γ > 0.005 and as a Class II pore when γ ≤ 0.005, and establish a pore-permeability relationship between the connected pore volume percentage a and the absolute permeability k of the connected pore space of the Class I pore and Class II pore reservoir samples respectively by least square fitting, to realize pore-permeability relationship construction based on connected pore equivalent structures.

6. A computer device, comprising: The computer device includes a processor and a memory, the memory is configured to store at least one computer program, the at least one computer program is loaded and executed by the processor to implement the heterogeneous reservoir pore-permeability relationship construction method in any one of claims 1-4.

7. A storage medium, characterized by The storage medium is configured to store at least one computer program, the at least one computer program is configured to implement the heterogeneous reservoir pore-permeability relationship construction method in any one of claims 1-4.

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