Emerging Scientists Session
Coupled multiphysics modelling of fluid injection-induced seismicity
- Prof. Wenzhuo Cao
- Imperial College London
Biography
Dr Wenzhuo Cao is an Assistant Professor of Coupled Subsurface Processes at Utrecht University, the Netherlands. He holds a PhD degree from Imperial College London, where he worked as a Research Associate and then a LKAB Research Fellow before joining Utrecht University. He has expertise and experience in geomechanics, rock physics, engineering seismology and resource evaluation in geo-energy deployment and mineral resources exploitation. His main research interests are in the areas of reservoir geomechanics and mining rock mechanics, with emphasis on coupled multiphysics and induced seismicity applied to a range of engineering applications such as CO2 geological storage, deep geothermal systems, aquifer thermal energy storage, hard rock/coal mining, and shale gas exploitation. He was selected as a Future Leader of American Rock Mechanics Association (ARMA). He serves as the founding member of the Underground Storage and Utilization Technical Committee of ARMA, and the Product Lead for Thermal Energy and Nuclear Waste Storage.
Introduction of the Lecture
Induced seismicity associated with subsurface fluid injection have been a longstanding concern in several industrial applications relevant to the energy transition, including CO2 storage and geothermal energy systems. However, the combined effects of multiple physical processes involved, the presence of underlying fracture systems, and the complexity of fault slip dynamics, pose significant challenges to understanding and mitigating induced seismicity hazards. To overcome these challenges, we have developed coupled thermo-hydro-mechanical models that contain fracture networks or faults to simulate fluid injection-induced seismicity. The modelling methodology features direct coupling between different physics for explicit fractures, fractured rocks and their interactions, as well as indirect coupling through changes of material properties, such as stress-dependent fracture and rock permeabilities. This presentation will first introduce the equivalent porous medium modelling of fluid injection, which examines causal mechanisms of induced seismicity at play and quantifies the relative contribution of each individual mechanism. The presentation will then report on modelling results of fluid injection into fractured reservoir rocks to evaluate the slip susceptibility of natural fracture systems. Last, the explicit modelling of slip dynamic of a pre-existing fault subjected to fluid injection will be presented to elucidate the control of frictional properties on the slip behaviour.