CN-122016598-A - Ternary association modeling method for synergistic effect of reservoir minerals and principal elements

CN122016598ACN 122016598 ACN122016598 ACN 122016598ACN-122016598-A

Abstract

The invention relates to the technical field of reservoir analysis, in particular to a ternary association modeling method for the synergistic effect of reservoir minerals and principal elements. According to the method, firstly, the systematic deviation of different element measurement systems is evaluated by means of an initial core sample which is not affected by chemical displacement, then the element abundance and the mineral source abundance of the principal elements in reservoir minerals evaluated by the different element measurement systems are combined, abundance gaps are accurately analyzed, the generation condition of secondary amorphous gel is evaluated to determine permeability resistance parameters, the improvement condition of permeability before and after chemical displacement is evaluated to determine seepage improvement parameters, the mineral source abundance change of the principal elements is preset before and after chemical displacement is evaluated to determine mineral corrosion parameters, ternary association modeling is further carried out, and the evaluation accuracy of reservoir state change is improved.

Inventors

XUAN YINGLONG
JIN XIANGAO
WANG SHUKUN
LIU PAN
YANG XUEBAI
HUANG QIANGTAI
YU HAOTONG
ZHONG YUJIE

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: 20260512
Application Date: 20260224

Claims (10)

1. A method of ternary association modeling of reservoir minerals with a principal element synergy, the method comprising: The method comprises the steps of intercepting an initial core sample from a reservoir core, obtaining the pre-flooding permeability of the residual reservoir core, obtaining the post-flooding permeability after chemical displacement experiments are carried out on the residual reservoir core, and segmenting and sampling to obtain segmented core samples; Acquiring a measurement correction factor according to the deviation of the element abundance of a preset principal element in an initial core sample relative to the mineral source abundance, and acquiring the residual abundance of the secondary amorphous gel in each segmented core sample by combining the element abundance of the preset principal element in each segmented core sample with the mineral source abundance; Obtaining a permeability resistance parameter according to the residual abundance of the secondary amorphous gel in each segmented core sample, obtaining a mineral corrosion parameter according to the difference between the mineral source abundance of the preset principal element in the initial core sample and the segmented core sample, and determining a seepage improvement parameter according to the pre-flooding permeability and the post-flooding permeability; and performing ternary association reservoir evaluation based on the permeability resistance parameter, the mineral erosion parameter and the seepage improvement parameter.
2. The method for ternary association modeling of a reservoir mineral and a principal element synergistic effect according to claim 1, wherein the method for obtaining the element abundance and the mineral source abundance comprises: For each core sample, determining the content of preset principal elements, the content of preset inert elements and the mineral content of crystal minerals containing the preset principal elements, wherein the preset inert elements do not comprise the preset principal elements; Determining the abundance of the mineral source of the preset prime element based on the proportional relation between the content of the mineral source of the preset prime element and the content of the preset inert element.
3. The method for modeling ternary association of a reservoir mineral with a principal element according to claim 1, wherein the method for obtaining the measured correction factor comprises: and taking the ratio of the element abundance of the preset principal element to the mineral source abundance in the initial core sample as a measurement correction factor.
4. The method for ternary association modeling of a reservoir mineral and a principal element synergy as claimed in claim 1, wherein the method for obtaining the residual abundance comprises: for each segmented core sample, weighting the mineral source abundance of a preset principal element by using the measurement correction factor, and determining the residual abundance of the secondary amorphous gel according to the deviation of the weighting result relative to the element abundance of the preset principal element.
5. The method for ternary association modeling of a reservoir mineral and a principal element in synergy according to claim 1, wherein the method for obtaining the osmotic resistance parameter comprises the following steps: Acquiring a distribution aggregation parameter according to the distribution characteristics of the residual abundance of the secondary amorphous gel in each segmented core sample; acquiring a residual blocking parameter according to the accumulated characteristics of the residual abundance of the secondary amorphous gel in all the segmented core samples; and fusing the distribution aggregation parameter and the residual blocking parameter to obtain the permeability resistance parameter of the residual reservoir core.
6. The method for ternary association modeling of a reservoir mineral and a principal element synergy as claimed in claim 5, wherein the method for obtaining the distribution aggregation parameter comprises: The method comprises the steps of determining a uniform distribution probability based on the segmented duty ratio of a single segmented core sample in the remaining reservoir cores, determining an actual distribution probability based on the duty ratio of the residual abundance of each segmented core sample in the sum of the residual abundance of all segmented core samples, and determining a distribution aggregation parameter based on the difference between the uniform distribution probability and the actual distribution probability.
7. The method for ternary association modeling of a reservoir mineral and a principal element synergistic effect according to claim 1, wherein the method for obtaining the mineral erosion parameter comprises the following steps: Determining the abundance of the driven mineral sources of the preset principal elements after the chemical displacement experiment based on the average characteristics of the abundance of the mineral sources of the preset principal elements in all the segmented core samples, and acquiring mineral erosion parameters according to the difference between the abundance of the mineral sources of the preset principal elements and the abundance of the driven mineral sources in the initial core sample.
8. The method for ternary association modeling of a reservoir mineral and a principal element synergistic effect according to claim 1, wherein the method for obtaining the seepage improvement parameter comprises the following steps: And acquiring seepage improvement parameters based on the proportional relation between the pre-flooding permeability and the post-flooding permeability.
9. The method for ternary association modeling of a reservoir mineral and a principal element synergistic effect according to claim 1, wherein the ternary association reservoir evaluation based on the osmotic resistance parameter, the mineral erosion parameter and the seepage improvement parameter comprises: constructing a ternary association evaluation model based on the penetration resistance parameter, the mineral erosion parameter and the seepage improvement parameter: Judging reservoir clogging when the seepage improvement parameter is smaller than a preset improvement threshold, wherein reservoir sediment clogging is judged if the seepage resistance parameter is larger than the preset resistance threshold, and reservoir non-sediment clogging is judged if the seepage resistance parameter is smaller than or equal to the preset resistance threshold; Judging reservoir corrosion when the seepage improvement parameter is larger than a preset improvement threshold value and the mineral corrosion parameter is larger than a preset corrosion threshold value; the reservoir is determined to be in an inert or corrosion-precipitation equilibrium state except for reservoir plugging and reservoir corrosion.
10. The method of ternary association modeling of reservoir minerals in conjunction with a principal element of claim 1, wherein segmenting the sample to obtain segmented core samples comprises: After the chemical displacement experiment, segmented core samples with consistent lengths are respectively cut out from the head, the tail and the middle of the residual reservoir core.

Description

Ternary association modeling method for synergistic effect of reservoir minerals and principal elements Technical Field The invention relates to the technical field of reservoir analysis, in particular to a ternary association modeling method for the synergistic effect of reservoir minerals and principal elements. Background In the field of enhanced oil recovery of chemical Flooding in petroleum engineering, alkali ternary complex Flooding (ASP Flooding) is a mature and key technology for reducing the interfacial tension of oil and water and improving the oil washing efficiency by injecting a chemical agent containing alkali, surfactant and polymer into an underground reservoir. However, strong alkaline environments induce non-congruent corrosion reactions in reservoir rock Dan Gujia minerals (e.g., feldspar, quartz, and clay minerals) which tend to form secondary amorphous gels (e.g., hydrated aluminosilicates or siliceous gels) in the pore throats, resulting in reduced reservoir permeability and lower recovery, and therefore analysis of reservoir state changes after chemical flooding is critical. Conventional X-ray diffraction (XRD) techniques rely on lattice diffraction peaks and cannot identify secondary amorphous gels lacking characteristic diffraction peaks, making it difficult to reveal contradictory phenomena in which the amount of mineral erosion is significant (the porosity theoretically increases) but the permeability is greatly reduced (actually blocked). Meanwhile, the heterogeneity of the reservoir causes chromatographic separation of chemical agents in the advancing process, so that secondary amorphous gel is unevenly distributed in the reservoir space, the existing averaging evaluation method ignores the spatial distribution difference, and high resistance risks such as end effect or throat shrinkage are easily ignored, so that the reservoir state change analysis accuracy is low. Disclosure of Invention In order to solve the technical problem of low accuracy of reservoir state change analysis in the prior art, the invention aims to provide a ternary association modeling method for the synergistic effect of reservoir minerals and principal elements, and the adopted technical scheme is as follows: The method comprises the steps of intercepting an initial core sample from a reservoir core, obtaining the pre-flooding permeability of the residual reservoir core, obtaining the post-flooding permeability after chemical displacement experiments are carried out on the residual reservoir core, and segmenting and sampling to obtain segmented core samples; Acquiring a measurement correction factor according to the deviation of the element abundance of a preset principal element in an initial core sample relative to the mineral source abundance, and acquiring the residual abundance of the secondary amorphous gel in each segmented core sample by combining the element abundance of the preset principal element in each segmented core sample with the mineral source abundance; Obtaining a permeability resistance parameter according to the residual abundance of the secondary amorphous gel in each segmented core sample, obtaining a mineral corrosion parameter according to the difference between the mineral source abundance of the preset principal element in the initial core sample and the segmented core sample, and determining a seepage improvement parameter according to the pre-flooding permeability and the post-flooding permeability; and performing ternary association reservoir evaluation based on the permeability resistance parameter, the mineral erosion parameter and the seepage improvement parameter. Further, the method for obtaining the element abundance and the mineral source abundance comprises the following steps: For each core sample, determining the content of preset principal elements, the content of preset inert elements and the mineral content of crystal minerals containing the preset principal elements, wherein the preset inert elements do not comprise the preset principal elements; Determining the abundance of the mineral source of the preset prime element based on the proportional relation between the content of the mineral source of the preset prime element and the content of the preset inert element. Further, the method for obtaining the measurement correction factor comprises the following steps: and taking the ratio of the element abundance of the preset principal element to the mineral source abundance in the initial core sample as a measurement correction factor. Further, the method for obtaining the residual abundance comprises the following steps: for each segmented core sample, weighting the mineral source abundance of a preset principal element by using the measurement correction factor, and determining the residual abundance of the secondary amorphous gel according to the deviation of the weighting result relative to the element abundance of the preset principal element. Further, the