A coupled geomechanics and fluid flow model for induced seismicity prediction in oil and gas operations and geothermal applications

The combined horizontal drilling and hydraulic fracturing has revitalized economically viable production from tight oil and gas shale reservoirs. This joint technology application enabled extensive unconventional resource exploration and development activities first in the United States followed by around the globe for unlocking the vast hydrocarbon resources. While the contributions from these accomplishments also created an enhancement in the local economies and technological advancements, these activities also have raised significant concern on potential surface and groundwater contamination and air pollution issues and more recently induced seismicity for geohazard risk. In this research study, we provide a summary of induced seismic activities related to oil, gas and geothermal operations in the U.S. The role of the stress alteration and behavior of physicochemical interactions taking place between the fracturing fluids used and the shale matrix under stress have been presented using a coupled geomechanics, fluid flow and physicochemical model. Examples of fluid injection in shale reservoir hydraulic fracturing and waste disposal operations have been provided toward better understanding of the predictive methodologies for induced seismicity and preventive effort for sustainable and safe unconventional operations. The impact of the presence of a fault at various distances away from the injection site nearby the disposal and injection operations on occurrence of the induced seismicity was studied. It was shown that microseismic monitoring along with the coupled geomechanics, fluid flow models and statistical analysis of the microseismic data can provide a good lead for prediction of potential fault reactivation and induced seismicity generation in association with oil and gas production, EOR and EGS fluid injection and waste disposal operations.