CN-121997833-A - Numerical simulation method and system for seepage and suction rule of displacement fluid and shale rock

CN121997833ACN 121997833 ACN121997833 ACN 121997833ACN-121997833-A

Abstract

The invention relates to the technical field of model construction, in particular to a displacement fluid and shale rock imbibition law numerical simulation method and system. According to the method, the regularization parameters of a regression algorithm are dynamically adjusted by quantitatively analyzing the linear association degree of granularity and experimental capillary constant distribution and the disturbance degree of local characteristic points, the contact angle determined by combining the permeability characteristic data of probe liquid is based on precisely calibrated capillary constants, the free energy of the shale surface is obtained through decoupling of a surface energy component theoretical model, the interface action state of displacement fluid, shale and crude oil is reflected by the three-phase contact angle determined through a three-phase equilibrium relation, and the adhesion work required by shale oil stripping is obtained. According to the invention, by establishing a high-precision fitting model of granularity and capillary constant and combining a surface energy component theory, more accurate calculation of shale oil stripping adhesion work is realized, and a reliable numerical simulation basis is provided for improving shale oil recovery ratio.

Inventors

KUANG TIE
LI LIANGNAN
LI BINHUI
LAN YUBO
HE XIN
SHI LIANG
CHU YANPING
WANG YAN
TANG WANQUAN
HE LIANQIN

Assignees

大庆油田有限责任公司
中国石油天然气股份有限公司

Dates

Publication Date: 20260508
Application Date: 20260130

Claims (10)

1. A method for numerically simulating a seepage and absorption law of displacement fluid and shale rock, which is characterized by comprising the following steps: obtaining experimental capillary constants of a plurality of groups of standard particle samples with different particle sizes; Based on the distribution characteristics of the granularity and the experimental capillary constant, analyzing the linear association degree and the local characteristic point disturbance degree of the related distribution, dynamically adjusting regularization parameters of a regression algorithm according to the linear association degree and the local characteristic point disturbance degree, and constructing a fitting relation model of the granularity and the capillary constant; Determining the permeability characteristic data of different probe liquids in the shale powder to be tested according to the granularity of the shale powder to be tested, determining the contact angle of each probe liquid by combining the calibrated capillary constant, and decoupling by using a surface energy component theoretical model based on the contact angle and the surface energy parameter of each probe liquid to obtain the surface free energy of the shale powder to be tested; The method comprises the steps of measuring the contact angle of displacement fluid and shale powder to be measured and the contact angle of shale oil and shale powder to be measured, combining the surface free energy of the shale powder to be measured to obtain solid-liquid interface energy and solid-oil interface energy, measuring the oil liquid interface energy of the shale oil and the displacement fluid, combining the solid-liquid interface energy and the solid-oil interface energy, determining the three-phase contact angles of the shale oil, the displacement fluid and the shale powder to be measured through a three-phase balance relation, and analyzing the adhesion work required by shale oil stripping based on the three-phase contact angles.
2. The method for numerically simulating the imbibition law of displacement fluid and shale rock according to claim 1, wherein the method for acquiring the linear correlation degree comprises the following steps: The method comprises the steps of carrying out standardization processing on data of granularity and experimental capillary constants to obtain two-dimensional data points, constructing difference feature vectors between each two-dimensional data point after standardization and adjacent data points, calculating the directional similarity between two adjacent difference feature vectors, and determining the linear association degree based on the average value of the directional similarity of all adjacent vectors.
3. The method for numerically simulating the imbibition law of displacement fluid and shale rock according to claim 2, wherein the method for acquiring the disturbance degree of the local characteristic points comprises the following steps: And calculating the polar difference of the characteristic characterization values of all the two-dimensional data points, and taking the ratio of the polar difference to the linear association degree as the disturbance degree of the local characteristic points.
4. A method for numerically modeling a imbibition law of a displacement fluid and shale rock according to claim 3, wherein the method for obtaining the fitting relation model comprises: The method comprises the steps of processing a characteristic characterization value by using a threshold segmentation method, counting the total number of two-dimensional data points with the characteristic characterization value smaller than a segmentation threshold, multiplying the total number by the disturbance degree of local characteristic points to obtain fitting correction force, and correcting preset initial regularization strength by using the fitting correction force to obtain an adjusted regularization parameter; fitting the granularity and experimental capillary constant by using a ridge regression algorithm containing the regularized parameters after adjustment to obtain a fitting relation model.
5. The method for numerically simulating the imbibition law of displacement fluid and shale rock according to claim 1, wherein the method for acquiring the contact angle of each probe liquid comprises the following steps: and obtaining the contact angle of each probe liquid by using a permeation dynamics equation based on the permeation rate related parameter, the viscosity and the surface tension of each probe liquid and a calibrated capillary constant.
6. The method for numerically simulating the imbibition law of displacement fluid and shale rock according to claim 1, wherein the method for acquiring the surface free energy of the shale powder to be tested comprises the following steps: substituting the contact angle and the surface energy parameters of the probe liquid with at least two known dispersion components and polar components into OWRK equation to construct a linear regression model; determining the slope and the intercept of a model through linear regression, determining the polar component of shale powder to be detected based on the slope, determining the dispersion component of the shale powder to be detected based on the intercept, and summing the polar component and the dispersion component of the shale powder to be detected to obtain the surface free energy of the shale powder to be detected.
7. The method for numerically simulating the imbibition law of displacement fluid and shale rock according to claim 1, wherein the method for acquiring the solid-liquid interface energy and the solid-oil interface energy comprises the following steps: acquiring solid-liquid interface energy according to the contact angle of the displacement fluid and shale powder to be detected, the surface tension of the displacement fluid and the surface free energy of the shale powder to be detected by utilizing a Young equation; And acquiring the solid-oil interfacial energy according to the contact angle of shale oil and shale powder to be detected, the surface tension of the shale oil and the surface free energy of the shale powder to be detected by utilizing a Young equation.
8. The method for numerically simulating the imbibition law of displacement fluid and shale rock according to claim 1, wherein the method for acquiring the three-phase contact angle comprises the following steps: and analyzing the three-phase interface equilibrium relation based on the solid-liquid interface energy, the solid-oil interface energy and the oil liquid interface energy to obtain the three-phase contact angles of shale oil, displacement fluid and shale powder to be tested.
9. The method for numerical simulation of the imbibition law of displacement fluid and shale rock according to claim 1, wherein the adhesion work is obtained by combining a three-phase contact angle and oil interface energy.
10. A displacement fluid and shale rock imbibition law numerical simulation system comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor performs the steps of a displacement fluid and shale rock imbibition law numerical simulation method according to any one of claims 1-9 when executing the computer program.

Description

Numerical simulation method and system for seepage and suction rule of displacement fluid and shale rock Technical Field The invention relates to the technical field of model construction, in particular to a displacement fluid and shale rock imbibition law numerical simulation method and system. Background In shale oil reservoir development, the displacement fluid spontaneously absorbs and replaces crude oil in shale micro-pores through imbibition, and the core is the accurate characterization of the interaction energy among the displacement fluid, shale rock and crude oil, which directly determines the optimization direction of the displacement fluid formula and the recovery ratio improving effect. However, the shale oil reservoir has the characteristics of nano-scale pore network, high clay mineral content, strong heterogeneity and the like, so that the correlation of granularity and capillary constant is obviously influenced by pore structure difference, the existing research is focused on a conventional sandstone reservoir, the specificity of a clay-organic matter composite interface in the shale oil reservoir is ignored, and the applicability of the existing model in the shale oil reservoir is limited. In the prior art, by constructing a rock nano pore and multicomponent shale oil molecular model by utilizing a molecular simulation technology, the density distribution, adsorption phase quality and movement track of each component in the pore in an equilibrium state are obtained, and the total interaction energy is obtained based on track analysis strategy analysis, so that the evaluation and analysis of the interaction energy among the components are realized. However, in the molecular simulation technology, the strong heterogeneous characteristics in the unconventional oil reservoir cannot be reflected, the calculation of the interaction energy is influenced, the actual calculation results in larger deviation between the numerical value of the interaction energy obtained by actual calculation and the actual interaction energy, the possibility of aggravating the deviation of the calculation of the interaction energy exists, the imbibition rule of the displacement fluid and shale rock cannot be accurately reflected, the formula optimization of the displacement fluid is difficult to be effectively guided, and the development efficiency of the shale oil reservoir is further restricted. Disclosure of Invention In order to solve the technical problems that in the prior art, the actual calculation results in larger numerical value of interaction energy and actual deviation, the possibility of aggravating the calculation deviation of the interaction energy exists, and the imbibition rule of the displacement fluid and shale rock cannot be accurately reflected, the invention aims to provide a numerical simulation method and a numerical simulation system of the imbibition rule of the displacement fluid and shale rock, and the adopted technical scheme is as follows: the invention provides a displacement fluid and shale rock imbibition law numerical simulation method, which comprises the following steps: obtaining experimental capillary constants of a plurality of groups of standard particle samples with different particle sizes; Based on the distribution characteristics of the granularity and the experimental capillary constant, analyzing the linear association degree and the local characteristic point disturbance degree of the related distribution, dynamically adjusting regularization parameters of a regression algorithm according to the linear association degree and the local characteristic point disturbance degree, and constructing a fitting relation model of the granularity and the capillary constant; Determining the permeability characteristic data of different probe liquids in the shale powder to be tested according to the granularity of the shale powder to be tested, determining the contact angle of each probe liquid by combining the calibrated capillary constant, and decoupling by using a surface energy component theoretical model based on the contact angle and the surface energy parameter of each probe liquid to obtain the surface free energy of the shale powder to be tested; The method comprises the steps of measuring the contact angle of displacement fluid and shale powder to be measured and the contact angle of shale oil and shale powder to be measured, combining the surface free energy of the shale powder to be measured to obtain solid-liquid interface energy and solid-oil interface energy, measuring the oil liquid interface energy of the shale oil and the displacement fluid, combining the solid-liquid interface energy and the solid-oil interface energy, determining the three-phase contact angles of the shale oil, the displacement fluid and the shale powder to be measured through a three-phase balance relation, and analyzing the adhesion work required by shale oil stripping based on the three-phase c