Integrated Rock Physics Studies and 3D Seismic Surveys to Evaluate CO₂ Sequestration in the SACROC Field, Texas

Brian Lipinski¹, Christopher Purcell¹, William Harbert¹, Yee Soong², Robert McLendon², Robert Hardage³, Rebecca Smyth³, Igor Haljasmaa², Dustin McIntyre², and Sinisha Jay Jikich^4
1Department of Geology and Planetary Science, University of Pittsburgh, Pittsburgh, PA
²National Energy Technology Laboratory, United States Department of Energy, Pittsburgh, PA
³Bureau of Economic Geology, Jackson School of Geosciences, University of Texas, Austin, TX
⁴RDS Inc, Morgantown, WV

The SACROC field is located in Scurry County, Texas and lies on the northeastern edge of the Permian Basin. It is the seventh largest onshore oil field in North America containing approximately 2.73 Billion Bbls of original oil in place. The main producing units are the Pennsylvanian aged Cisco and Canyon Formations. These are highly heterogeneous reef complexes that contain massive amounts of bedded bioclastic limestone and thin intercalcated shale beds. The average porosity is 7.1% with a permeability of approximately 31 mD. The depth to this reef complex is approximately 2040 meters. These units are a part of the larger carbonate platform called the Horseshoe Atoll.

The site is the oldest CO₂ enhanced oil recovery site in the United States with over 140 million metric tons of CO₂ injected since 1972. Recently, the National Energy Technology Laboratory of the United States Department of Energy has funded a combined carbon sequestration and enhanced oil recovery project at the site. In the first phase of the study, laboratory measurements of reservoir properties were collected at varying reservoir conditions. These measurements were then used to model the anticipated seismic response of the reservoir, which was then compared to 3D seismic data collected before a CO₂ flood. In the final phase of the study, successive surveys will be used to map CO₂ migration and asses the integrity of the overlying caprock, which are marine shale units of the Permian aged Wolfcamp Formation.

Presented AAPG Eastern Section Meeting, Pittsburgh, Pennsylvania 2008 © AAPG Eastern Section