Fault Interpretation and Slip Potential Analysis from Hydraulic Fracturing Across the Bowland Area in Central Britain

The Bowland Shale in central Britain, has shown to be very susceptible to induce anomalously large seismicity during hydraulic fracturing stimulations of shale-gas wells. In part, due to the presence of pre-existent, critically-stressed, strike-slip faults that are difficult to detect even in 3D seismic surveys due to their low vertical displacement, and only visible through the location and fault planes of microseismic events once these faults were reactivated. To better identify fault planes from 3D seismic images, and their reactivation potential due to hydraulic fracturing, a high-resolution fault-detection attribute was first tested in the same 3D seismic survey where the two most recently shale-gas wells were hydraulic-fractured in the Bowland Shale in 2018 and 2019. Their slip potential was then estimated by integrating the obtained faults with the formation’s stress and pore pressure conditions, where several critically stressed faults were identified near the previously hydraulic fractured wells and with similar location and orientation than the induced seismicity reported for the same wells. We then implemented the same methods in another six 3D seismic datasets from across central Britain, where we observed a regional reduction in the intensity of mapped faults from west to east.