Investigation of Faults Activation Mechanisms in Carbon (CO2) Storage

CHEVRON/NAZARBAYEV UNIVERSITY RESEARCH COLLABORATION Faculty-Development Competitive Research Grants Program

Carbone dioxide (CO2) Capture and Storage (CCS) is the process of collecting CO2 produced by mankind's activities and injecting it into subsurface geologic storage sites to isolate CO2 from the atmosphere. The focus of this project is fault activation aspects of the CO2 storage stage. With an increase in demand for CCS and the number of CO2 storage sites, there is a need for a better understanding of mechanisms involved in CO2 storage and leakage to the environment. CO2 can be stored in Saline aquifer formations, depleted oil and gas reservoirs, unminable coal seams, or other porous formations.
To safely store Carbone dioxide, it is vital to ensure the integrity of the caprock during the CO2 injection process and production within a reservoir. A change in fluid pressure and temperature within a geological reservoir/formation affects the regional in-situ stress within the reservoir and surrounding rock. Accordingly, the potential hazards associated with the CO2 storage are the reactivation of major pre-existing discontinuities and faults and the creation of new fractures within the caprock zone, which may breach the hydraulic integrity of the storage site.
The objective of this research work is to conduct a comprehensive numerical study of fault activation mechanisms and delve into the mechanisms involved in fault reactivation processes in CO2 storage. The main components of caprock assessment, as a seal for Carbone monoxide storage, are the analysis of caprock capacity, caprock geometry, and caprock integrity. Faults constitute a major component of geological formations and change the rock mass system mechanical behaviour significantly, in particular at large scales. The focus of this research is to conduct a comprehensive analysis of fault mechanical response to pressure field induced by the CO2 injection and caprock in-situ performance and evidence of potential leakage from the faults.