Comprehensive Evaluation of Fault Sealing for CO ₂ Geological Storage in Low‐Permeability Reservoirs

Abstract

ABSTRACT CO 2 storage in low‐permeability reservoirs is a key technology for achieving the strategic goals of carbon peak and carbon neutrality. The evaluation of the sealing performance of the geological storage body is an important measure to ensure the safe storage of CO 2 . The injection of CO 2 into the reservoir may cause fault instability within the geological storage body, leading to CO 2 leakage. Therefore, it is particularly important to assess the fault sealing integrity for CO 2 storage. This study integrates geological and mechanical theories to establish a multiparameter evaluation methodology for fault sealing in CO 2 storage within low‐permeability reservoirs. By utilizing seismic interpretation data, laboratory experiments, and stress analysis via a three‐dimensional geomechanical model, the methodology achieves a quantitative assessment of fault sealing performance. This evaluation system comprehensively considers both the lateral and vertical sealing of faults, integrated with mechanical analysis. It enables a comprehensive evaluation of fault sealing under CO 2 storage conditions. The research indicates that, from a geological perspective, the fault sealing integrity of the G block is predominantly low to medium risk, and the overall sealing performance is favorable. In terms of mechanical integrity, the fault sealing safety factor is high. The fault is resistant to tensile rupture and shear slip, and the sealing integrity is good. The multiparameter evaluation method proposed in this article fully incorporates the influence of both geological and mechanical factors on fault sealing in CO 2 storage, providing a scientific basis for the evaluation of geological seal integrity and the prevention and control of leakage risks in CO 2 storage projects.

Affiliated Institutions

• State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation CN
• Southwest Petroleum University CN

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