An evaluation method for a leakage risk area in the process of CO2 geological storage

Abstract

The invention relates to an evaluation method of a leakage risk area in the process of CO2 geological storage. Based on the principle of sedimentary microfacies constraint, rock mechanics parameters of cap rock are obtained, and the appropriate fracture pressure prediction model is selected to evaluate the mechanical sealing of the cap rock, the fine geological model and numerical model are utilized, and reservoir numerical simulation theory is used, and the dynamic changes of CO2 injection process and CO2 saturation in the sealing body until the sealing period of 200 years are studied throughthe established numerical model of the sealing body to study. Based on the concept of fluid potential and potential gradient in oil and gas migration theory and the dynamic distribution of CO2 saturation, the migration direction and accumulation area of CO2 are analyzed, and the transverse CO2 leakage risk is predicted according to the migration direction and distribution characteristics of CO2 in the reservoir and the boundary of the reservoir sand body. Based on the distribution characteristics of the fracture pressure of the cap rock and the dynamic distribution characteristics of the pressure in the sealing body, the possible longitudinal leakage risk area along the CO2 migration path is quantitatively studied by using the proposed discriminant formula for the risk area of the cap rock fracture. This method not only flooding oil in low permeability reservoir, but also realizing safe and efficient carbon sequestration has important practical application value.

Description

Technical field [0001] This invention belongs to CO 2 The field of safety assessment of geological storage, involving a kind of CO 2 CO during geological storage 2 Through the comprehensive evaluation and prediction method of the risk area of ​​the cover layer leakage. Background technique [0002] Climate change is a common challenge facing human society today, reducing CO in the atmosphere 2 It has become a global consensus to protect the human environment. In various emission reduction schemes, CO 2 CCS-Carbon Capture and Storage technology can significantly reduce the CO produced by fossil fuels in the atmosphere. 2 Emissions have great potential for emission reduction and are valued by countries all over the world. And in the existing CO 2 In geological storage technology, CO 2 Injecting into abandoned or mid- and late-stage oil and gas fields for flooding and storage is preferred by countries all over the world for its economic efficiency. CO stored in oil and gas reservoi...

AI Technical Summary

Problems solved by technology

This method focuses on solving the problem of obtaining cap rock mechanical parameters and selecting a fracture pressure prediction model when the core data of the reservoir and cap rock are insufficient and unmatched; CO 2 Dynamic change of pressure in the storage body and CO 2 Transport accumulation dynamic distribution and CO 2 Prediction method of leakage risk area

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