Optimizing Drilling and Completions in a Gas Shale - Microseismic Monitoring in North America

Commercially driven development of oil and gas shale reservoirs usually requires hydraulic fracture stimulation to create induced fractures that connect naturally-occurring, hydrocarbon-filled fracture networks with the producing wellbore. The use of microseismic monitoring during hydraulic stimulation has become a standard practice in the development of most North American unconventional resource plays, providing rapid and significant improvements in completion efficiency. The reservoir parameters determined from monitoring include the local orientation of maximum stress, the volume of reservoir contacted by the induced fractures and reactivated natural fractures, and the dimensions of the induced fracture network on a stage by stage basis. This paper will discuss case histories from several US gas shale basins, presenting the development issues being addressed by the stimulation monitoring and how the microseismic monitoring provided direct answers to these problems. Also discussed is the use of temporary surface and permanent near-surface geophone arrays for data acquisition to expand the range of monitoring applications beyond those available from traditional borehole-located geophone array monitoring.