Study of a regional three-dimensional seismic data set by Cumella and Ostby (2003) indicated the potential existence of wrench faults in the southern Piceance Basin, Colorado. Although the faults could be inferred to cut through the productive interval, no direct observation was possible until the Reservoir Characterization Project (RCP) conducted a multicomponent seismic study at Rulison Field. The study confirms the existence of faults and documents their importance in creating fracture zones critical to higher expected ultimate recovery (EUR) well production within the field.

Three-dimensional seismic data were acquired at Rulison Field by RCP to investigate whether zones of high fracture density within the Mesaverde reservoir interval could be detected. Three time-lapse, multicomponent seismic surveys were acquired in 2003, 2004, and 2006. The study confirmed the existence of wrench faults, documented zones of high fracture density, and observed pressure depletion within these zones. Wrench faults and fracture zones play an important role in the creation of “sweet spots” associated with wells of high EUR. Sweet spot identification with multicomponent seismic data can improve the economics of tight gas exploration and production.