Geophysics professor Tom Davis presented results of Phase XI of the Reservoir Characterization Project (RCP) to a packed house of sponsors at a spring meeting at the Colorado School of Mines in Golden, Colorado.

The Phase XI project focused on nine-component, full-wave seismic data collected at Rulison Field, in western Colorado's Piceance Basin. Three multi-component seismic surveys were acquired in 2003, 2004 and 2006 across the same area, enabling interpretation of the efficacy of time-lapse data.

Additionally, a downhole test that measured in-situ pore pressure was carried out on a field well within the study area, and multi-component microseismic data were recorded during a four-stage hydraulic fracture treatment on a nearby well.

To date, RCP's Phase XI graduate students have concluded that shear waves are the most valuable wave mode for characterizing and monitoring Rulison's Williams Fork and Iles tight-gas sands. The RCP project also validated the use of nine-component seismic data for detecting faults and fractures, detecting and predicting lithology and pressures, monitoring reservoir connectivity and depletion, and locating prime well locations.

Pressure-test results were able to show a correlation with depletion zones that were predicted from time-lapse shear-wave data. Furthermore, the data showed coincidence with depleted areas in the Cameo Coal interval.

High-resolution dynamic reservoir characterization appears to be a key technology for tight gas, Davis said, as it gives operators the potential to improve recovery efficiencies.

Going forward, RCP is circulating research proposals for its Phase XII project. Under consideration is dynamic reservoir characterization on Postle Field, in Texas County, Oklahoma. Postle's Morrow reservoir is undergoing enhanced oil recovery using CO2, a very germane subject in today's oil field.