Thermo-hydro-mechanical modeling of induced seismicity in carbon sequestration projects

• Main Author: Mortezaei, Kimia
• Other Authors: John F. Peters
• Format: Others
• Language: en
• Published: MSSTATE 2016
• Subjects: Civil and Environmental Engineering
• Online Access: http://sun.library.msstate.edu/ETD-db/theses/available/etd-09062016-115048/

<p>The ultimate goal of this project is to comprehensively investigate induced seismicity potential by studying the behavior of fault shear zones during high pressure CO₂ injection for utilization and storage operations. Seismicity induced by fluid injection is one of the major concerns associated with recent energy technologies such as Carbon capture and storage (CCS) projects. CO₂ injection increases reservoir pore pressure and decreases the effective stress causing deformation that can degrade the storage integrity by creating new fractures and reactivating faults. The first consequence is that reactivation of faults and fractures create a pathway for upward CO₂ migration. The increased seismic activity is the second consequence, which raises the public concern despite the small magnitudes of such earthquakes.</p> <p>Changes in pore fluid pressure within the injection zone can induce low-magnitude seismic events. However, there are multiple involved Thermo-Hydro-Mechanical (THM) processes during and after fault slip that influences pore pressure and fault strength. Flash heating and thermal pressurization are two examples of such processes that can weaken the fault and decrease frictional resistance along the fault. </p> <p>The proposed study aims to use a multi-physics numerical simulation to analyze the fault shear zone mechanics and capture the involved THM processes during CO₂ injection. In one study, a coupled THM model is performed to simulate stress and pore pressure changes in the fault and ultimately measuring the maximum induced magnitude. The other study investigates the response of the fault shear zone during CO₂ injection with and without considering the thermal pressurization (TP) effect. In the third part, the realistic behavior of friction was studied by using a rate-and-state friction theory to capture the full earthquake rupture sequence. The outcome of the proposed project can significantly increase the efficiency and public acceptance of CCS technology by addressing the major concerns related to the induced seismicity due to CO₂ injection.</p>