A research-focused large-scale carbon dioxide (CO2) injection at Cranfield Field, Mississippi, conducted as part of the Southeast Regional Sequestration Partnership (SECARB), is building experience in technologies and approaches that may be valuable in commercial deployment of CO2 storage projects. Since July 2008, more than 3 million tons of CO2 have been injected into a 25 m thick interval of the Lower Tuscaloosa Formation at 3.2 km depth, with the general goal of providing policy makers with the information needed to increase confidence in CO2 geologic storage capacity predictions and retention estimates. A suite of novel and traditional monitoring technologies was utilized to observe the evolution of the CO2 plume and obtain data about the performance of the reservoir in multiphase flow conditions. The monitoring program focused on above-zone pressure surveillance, down dip plume-edge mapping, and multiphase flow process in heterogeneous sandstone. The project started CO2 injection into the oil bearing formation of the field and advanced injection into the associated water leg, linking enhanced oil recovery (EOR) and downdip brine storage. Monitoring and injection continues through 2017.
Key findings: CO2 moved in preferential paths along fluvial channels. A number of successfully deployed imaging tools support this channel-dominated flow theory. CO2 moved downdip and not preferentially updip, indicating buoyancy forces were not flow dominating at the interwell scale of the experiment.
We hope results from this experimental project provide a strong foundation for transferable research and knowledge gain from the monitoring program, based on both strengths and weaknesses of applied monitoring technologies will be relevant for future commercial CO2 storage applications.
The U.S. Department of Energy (DOE) funded seven Regional Carbon Sequestration Partnerships (RCSP) in 2003 as part of its Carbon Sequestration Program. These partnerships are undertaking efforts to determine the best approaches and technologies to safely and permanently store carbon dioxide in geologic formations (NETL website). During the current development phase (phase III) of the partnerships, several large-scale projects aiming at injecting at least one million metric tons of CO2 are underway. The "Early Test" described in this paper, part of the Southeast Regional Carbon Sequestration Partnership (SECARB) led by the Southern States Energy Board (SSEB), was the first project in the U.S. (fifth in the world) to document that large injection volume under CCS monitoring conditions.
During the validation phase (phase II), SECARB undertook four tests: two Coal Seam Projects, the Saline Reservoir Field Test in Mississippi, and the Gulf Coast Stacked Storage Project. The latter preceded the Early Test and focused on developing pressure-based above zone monitoring over an extended period, as large volumes of CO2 were injected for enhanced oil recovery (EOR) at Denbury Onshore LLC operated Cranfield Field in Mississippi. The Gulf Coast Carbon Center (GCCC), a consortium functioning within the Bureau of Economic Geology (BEG) of the University of Texas at Austin is the technical leading institution for both the Gulf Coast Stacked Storage Project and the Early Test.