A HISTORIC LOOK AT HYDROCARBON PLAY TYPE, INDUCED SEISMICITY, STAKEHOLDER ENGAGEMENT, AND RISK MANAGEMENT IN OKLAHOMA, USA
The Woodford-Meramec play relies on hydraulic fracturing and has been developed since 2006. Because these wells do not produce large water volumes after recovery of stimulation fluids, associated seismicity is minimal. In the last 2 years, however, seismicity associated with this play has increased. This uptick corresponds to increasingly intense completions: more water, more proppant, higher pump rates. Geologic and engineering analysis of completions-related seismicity indicates that critically oriented faults are prone to reactivation as stimulation intensity increases (classic induced seismicity). The State and operators responded to this new situation by developing additional risk management protocols that involve defined stage gate for modifications or cessation of completions in response to proximal seismic activity. As these protocols reduce the percentage of a well bore that is optimally stimulated, operators must account for this reduction in pre-production economic forecasts.
The cooperation of Oklahoma’s regulators and operators to reduce seismic risk offers important lessons for defining specifics risks for different plays, so that risk management protocols match the value-drivers of different stakeholders. Open discussion and getting the science right are key to enacting informed public policy and the license to operate.