Simulating Subterranean Fluid Injection through Iteration on the VirtualQuake Model

TL;DR

This paper enhances the VirtualQuake earthquake simulation framework to model fluid injection effects, capturing both immediate and long-term impacts on fault stability and seismicity.

Contribution

It introduces a flexible, stable model using stress point sources with fluid injection simulation based on invasion percolation, enabling better risk assessment.

Findings

Repeated injections create persistent high-pressure zones.

Single injections produce limited stress changes.

Model captures long-term injection effects on fault stability.

Abstract

This work extends the VirtualQuake earthquake simulation framework to incorporate the effects of fluid injection on fault stability and induced seismicity. Reworking VirtualQuake into a system using stress point sources, instead of rectangular segments, the new model offers increased geometric flexibility, greater stability, and the re-addition of cross-fault interactions. This approach is paired with the addition of fluid injection modeling, through the distribution of inflationary stress sources, according to invasion percolation, simulating both the stress effect of the injection on nearby faults, and deformation from the injection itself. The model captures both immediate and long-term impacts of injection cycles, including hydraulic fracturing processes and post-injection pressure dissipation. Results show that while single injections produce limited stress changes, repeated injections generate persistent high-pressure regions that progressively destabilize nearby faults, increasing the likelihood of seismic events. This model evolution offers a tool for the evaluation and characterization of long term risks from commercial injection.