CN-122021090-A - Shale oil digital rock physical dynamic and static mechanical parameter relation characterization method

CN122021090ACN 122021090 ACN122021090 ACN 122021090ACN-122021090-A

Abstract

The invention provides a shale oil digital rock physical dynamic and static mechanical parameter relation characterization method, which comprises the steps of constructing a real geological feature digital rock block based on image identification; and obtaining dynamic and static parameter relations of the rock with various tattooing characteristics by adopting a rock dynamic and static mechanical simulation method with various tattooing characteristics. The difference of geological properties of different stratum characteristic digital rocks is reduced, and more continuous and accurate geological parameter data is provided through efficient digital simulation.

Inventors

LIU HAOJIE
CHEN YUMAO
CHEN FEI
LIU JIAQI
YUAN HAIHAN
YANG FENG
QIAN ZHI

Assignees

中国石油化工股份有限公司
中国石油化工股份有限公司胜利油田分公司

Dates

Publication Date: 20260512
Application Date: 20241112

Claims (11)

1. The shale oil digital rock physical dynamic and static mechanical parameter relation characterization method is characterized by comprising the following steps of: constructing a true geological feature digital rock block based on image recognition; constructing a plurality of physical attribute stratum digital rocks; And obtaining the dynamic and static parameter relation of the rock with various tattooing characteristics by adopting a rock dynamic and static mechanical simulation method with various tattooing characteristics.
2. The method for characterizing the physical dynamic and static mechanical parameter relationship of shale oil digital rock according to claim 1, wherein the constructing of the true geological feature digital rock based on image recognition specifically comprises the following steps: Acquiring a digital image containing the actual geological information of the tattoos; The digital image is subjected to image recognition technology and threshold segmentation to recognize various tattoo types, and a threshold segmentation result is obtained; And carrying out data processing on the threshold segmentation result to obtain the digital rock mass with the real geological characteristics.
3. The method for characterizing a shale oil digital petrophysical dynamic and dynamic parameter relationship according to claim 2, wherein the step of obtaining the digital image containing the tattoo real geological information comprises the following steps: and acquiring a digital image containing the actual geological information of the tattoos by adopting a means of actual observation photographing and core scanning of the outcrop.
4. The method for characterizing the physical dynamic and static mechanical parameter relation of shale oil digital rock according to claim 2, wherein the step of performing data processing on the threshold segmentation result to obtain the digital rock block with the real geological feature specifically comprises the following steps: And carrying out data processing on the threshold segmentation result, using a plurality of numbers to represent a plurality of tattoos, and finally obtaining data containing real tattoos information to obtain a real geological feature digital rock.
5. The method for characterizing the digital rock physical dynamic and static mechanical parameter relationship of shale oil according to claim 4, wherein the actual stratum layer information specifically comprises stratum layer development types, frequency and development thickness.
6. The method for characterizing the physical dynamic and dynamic parameter relationship of shale oil digital rock according to claim 1, wherein the construction of the various physical attribute stratum digital rock specifically comprises the following steps: Carrying out multi-angle coring on a digital rock block containing real stratum tattoo geological features, carrying out sample coring at intervals from the direction parallel to the stratum tattoo, and obtaining digital rock cores with various stratum obliquities; And constructing the digital rock blocks with various physical geometrical properties of the layers by adopting a controlled variable method and considering the thickness, the density and the types of the layers, wherein the background matrix is consistent with the actual stratum.
7. The method for characterizing a digital rock physical dynamic mechanical parameter relation of shale oil according to claim 1, wherein said constructing a digital rock with a plurality of physical geometrical properties of layers by adopting a controlled variable method and considering a plurality of thicknesses, densities and types of layers comprises: dividing the homogeneous sample into n parts, and setting the thickness of the homogeneous sample as sample height/n, sample height/2 n, sample height/3 n and sample height/4 n when setting various thickness layers; The number of the various layers is respectively 1,2,4 and 8; the setting of the various types of tattoos simulates the various types of tattoos by assigning various contact model parameters to the tattoos particles at the same location, the background matrix contact model parameters being set to the same value.
8. The method for characterizing a shale oil digital rock physical dynamic and static mechanical parameter relationship according to claim 6, wherein the interval angle is 15 °.
9. The method for characterizing a shale oil digital rock physical dynamic and static mechanical parameter relationship according to claim 1, wherein the rock dynamic and static mechanical simulation method adopting a plurality of stratum features comprises the following steps: After the mesoscopic parameter correction is carried out with an indoor experiment, digital rock mechanical numerical simulation tests of various stratum inclinations, various stratum thicknesses and various stratum densities are carried out, so that deformation characteristics under the action of large strain are obtained, and a stress-strain curve is obtained; And calculating static mechanical parameters to obtain the shale microscopic damage characteristics and the intrinsic mechanism of various stratum attributes, and exploring the influence of the inclination angle of the stratum on shale damage and the action mechanism thereof.
10. The method for characterizing the digital rock physical dynamic and static mechanical parameter relation of shale oil according to claim 9, wherein the developing digital rock mechanical numerical simulation test of various stratum obliquities, various stratum thicknesses and various stratum densities specifically comprises the following steps: Dynamic mechanical simulation is based on a finite element method; and solving the elastic mechanical problem by adopting a finite element method.
11. The method for characterizing a shale oil digital rock physical dynamic and static mechanical parameter relationship according to claim 10, wherein said solving an elasto-mechanical problem by using a finite element method specifically comprises: establishing an elastic potential energy equation, solving a displacement field and obtaining the elastic modulus of the digital rock core; the elastic potential energy equation establishment includes: According to the theory of elastic mechanics, the elastic potential energy of a cell is a function of the cell strain and the dielectric elastic constant, Wherein epsilon α ,ε β represents the cell strain, C αβ represents the elastic parameter of the medium, if the pixel of the digital core is used as a finite element unit body, and a cubic linear interpolation shape function is adopted to construct a finite element equation, the cell elastic potential energy equation is that, Wherein N represents a shape function matrix, L represents a shape function space deviation operator matrix, C represents a medium stiffness matrix, u represents a node displacement vector, D=N T L T CLN represents a unit stiffness matrix, if a Simpson numerical integration method is adopted on a unit, a unit elastic potential energy equation is written as, Where D xyz represents a Simpson integral point stiffness matrix, considering a periodic boundary condition, the potential energy function of the boundary cell has the form, Where the vector delta is related to where the cell is located; the general potential energy equation of the digital core is assembled by the unit potential energy equation, Wherein U is the displacement vector of all nodes, A is assembled by the unit rigidity matrix D according to the positions of the nodes, B is assembled by delta T D, and H is a constant.

Description

Shale oil digital rock physical dynamic and static mechanical parameter relation characterization method Technical Field The invention relates to the field of rock mechanics analysis in petroleum engineering, in particular to a shale oil digital rock physical dynamic and static mechanical parameter relation characterization method. Background Shale oil refers to petroleum existing in an organic shale layer, and has huge land shale oil resource potential in China and good exploration and development prospect (Du Jinhu and the like, 2019). In shale oil exploration and development processes, the elastomechanical parameters of rock are important geologic parameters (Liu Xiwu, et al, 2019) required by shale oil reservoirs in drilling, completion, hydraulic fracturing and other projects. The dynamic and static elastic mechanical parameters of the rock reflect the elastic mechanical characteristics of the rock under different loading conditions. Static parameters are obtained by slowly loading and measuring the deformation of the rock, while dynamic elastic parameters are usually obtained by sonic measurements or other fast dynamic methods. The difference between the two depends on the magnitude of the external load loading. Static parameters are mostly adopted in rock mechanical analysis and fracturing construction schemes, but the static parameters depend on experiments, and the rock core data has no continuity and is high in cost. Therefore, conversion of the mobile-static parameters is often required. Chinese patent 202010874979.0 discloses a rock dynamic mechanical parameter conversion method and system for an artificial rock core, wherein a series of dynamic and static rock mechanical parameters of the artificial rock core are obtained, regression fit is carried out to obtain a plurality of different functions and correlation coefficients, and dynamic and static parameter relations with strong correlation are optimized. Chinese patent 201611183911.8 discloses a method for converting dynamic and static elastic parameters of rock. By acquiring horizontal cores of different depths of the stratum, dynamic parameters and static parameters are measured under different pressures, and the clay content of the horizontal cores is measured. And (3) completing the conversion of the dynamic and static elastic parameters by establishing a functional relation between the ratio of the dynamic and static elastic parameters and the formation pressure and clay content. These methods also rely on a large number of core experiments, which are costly and costly, and therefore, there is a need to characterize the dynamic and static mechanical parameters of shale oil from the digital rock perspective. Disclosure of Invention In view of the foregoing, the present invention has been developed to provide a shale oil digital petrophysical dynamic and dynamic parameter relationship characterization method that overcomes or at least partially solves the foregoing problems. According to one aspect of the invention, there is provided a shale oil digital petrophysical dynamic and static mechanical parameter relation characterization method, the parameter relation characterization method comprising: constructing a true geological feature digital rock block based on image recognition; constructing a plurality of physical attribute stratum digital rocks; And obtaining the dynamic and static parameter relation of the rock with various tattooing characteristics by adopting a rock dynamic and static mechanical simulation method with various tattooing characteristics. Optionally, the constructing the image recognition-based real geological feature digital rock specifically includes: Acquiring a digital image containing the actual geological information of the tattoos; The digital image is subjected to image recognition technology and threshold segmentation to recognize various tattoo types, and a threshold segmentation result is obtained; And carrying out data processing on the threshold segmentation result to obtain the digital rock mass with the real geological characteristics. Optionally, the acquiring the digital image containing the tattooing real geological information specifically includes: and acquiring a digital image containing the actual geological information of the tattoos by adopting a means of actual observation photographing and core scanning of the outcrop. Optionally, the data processing is performed on the threshold segmentation result, and obtaining the digital rock block with the real geological feature specifically includes: And carrying out data processing on the threshold segmentation result, using a plurality of numbers to represent a plurality of tattoos, and finally obtaining data containing real tattoos information to obtain a real geological feature digital rock. Optionally, the real stratum layer information specifically comprises layer development types, frequency and development thickness. Optionally, the constructi