Summary
The Southwest Regional Partnership (SWP) of the United States Department of Energy Regional Carbon Sequestration Partnerships studying Carbon Capture, Utilization, and Storage (CCUS) is currently in the deployment phase (Phase III). As part of Phase III the SWP is characterizing, modeling, monitoring, and tracking at least one million metric tons of carbon dioxide (CO2) at an ongoing enhanced oil recovery (EOR) project operated by industry partner, Chaparral Energy, LLC (CELLC) in Ochiltree County, northern Texas. The production zone (Morrow Sandstone Formation) is a fluvial deposit with small scale heterogeneities posing challenges to site characterization and monitoring using surface seismic methods alone. In order to meet SWP’s multiple objectives, ranging from field scale site characterization to plume monitoring, the SWP has partnered with Schlumberger Carbon Services to conduct an extensive geophysical program. A combination of 3D surface, 3D vertical seismic profiles (VSPs), and cross-well surveying methods are being used to achieve multi-scale geophysical imaging for both site characterization and time-lapse monitoring.
Introduction
Acquiring multiple seismic measurements in a specific field is an operationally and financially challenging task. In the Farnsworth Project three seismic measurements technologies were employed, in conjunction with down-hole measurements, to address multiple objectives: Sub-surface imaging and characterizations, site characterization for optimization of an ongoing EOR program, and development of innovative monitoring methodologies for CO2 sequestration.
A high fidelity 3D surface seismic survey has been acquired to address the need for improved field-scale structural and stratigraphic interpretation, as well as to support estimation of storage capacity and geomechanical properties. 3D VSP and cross-well surveys are being acquired to supplement geologic detail through improved vertical resolution in the vicinity of the injection wells. Both borehole surveying techniques are being utilized for time-lapse monitoring of the injected CO2. The schedule of time-lapse monitor surveys is being dictated by the ongoing progressive transition of the unit from secondary production (water flood) to tertiary (CO2 Water-Alternating-Gas).
