Distributed acoustic sensing time-lapse vertical seismic profiling during zipper-fracturing operations: Observations, modeling, and interpretation

Abstract

Recent advances in distributed acoustic sensing (DAS) technology allow active seismic monitoring of stimulated rock volume (SRV) development. This study showcases an interstage DAS vertical seismic profiling (VSP) survey acquired during a zipper-fracturing stimulation. Incident P-waves scattered by the SRV and converted to S-waves are observed in the data. The signals are associated not only with hydraulic fracturing stages of the instrumented well, but also with fracturing of an adjacent well in the zipper group. A workflow is developed to monitor and characterize the SRV, fracture closure time, and interactions between zipper wells. 3D full wavefield modeling confirms the data interpretation and provides additional insight. As a result, we have been able to estimate SRV properties, including SRV height, width, and the fracture closure time for all wells within the zipper group. Moreover, for adjacent wells, the length and azimuth of SRV can be constrained. Our work provides critical information for optimizing hydraulic fracturing operations.