Analysis Of Microseismic Location Accuracy For Hydraulic Fracturing At The DWTI Site, Jasper, Texas

Abstract

This report presents the results of a feasibility study designed to assess whether microseismic location techniques can provide enough accuracy and precision to enable a high resolution study of the spatial distribution of microseismic events induced during a hydraulic fracture experiment. We calculated the 90% confidence regions for six synthetic microevent 'clusters' along the azimuth of a hydraulic fracture produced during Atlantic Richfield's 1993 Fracture Technology Field Demonstration Project in Jasper, Texas. Examination of the confidence regions for the absolute locations indicates that microseismic events can be confidently located for areas near the monitoring wells but away from the plane intersecting the two observation points. We determined that the resolution for events located at the ends of the fracture is poor but improves dramatically nearer the wells. The minimum dimensions of the 90% confidence regions for events within our study area are approximately 8 ft in the northwest-southeast direction, 3 ft in the northeast-southwest direction, and 3 ft in depth.