The Project ECO2S Phase 2 Carbonsafe Field Project

Mississippi Power Company (MPC), in conjunction with Southern Company Services (SCS), Advanced Resources and others performed considerable pre-feasibility work on the Project ECO₂S CO₂ Storage Complex.  This enabled the Project to qualify for the Phase II: Storage Complex Feasibility for CarbonSAFE initiated by the U.S. Department of Energy/National Energy Technology Laboratory (DOE/NETL).  The paper discusses the geological, engineering and other key steps that have enabled Project ECO₂S to proceed toward a commercial CO₂ storage facility.

1.   Performing Geologic Evaluation of the Proposed CO₂ Storage Site.  The first step was a comprehensive, multi-disciplinary study entitled, “Geological Evaluation of the Potential for CO₂ Sequestration in Kemper County, Mississippi,” performed by Dr. Jack Pashin of the Geological Survey of Alabama (GSA).   Funded by Southern Company, this study identified two Lower Cretaceous strata, the Paluxy and the Washita-Fredericksburg sandstone saline formations, and one Upper Cretaceous interval, the Lower Tuscaloosa Massive Sand, as geologically favorable for storing CO₂ in the Project ECO₂S area, Exhibit 1.  These three formations are overlain by the thick Tuscaloosa Marine Shale, a regionally extensive confining unit (seal).   This study and its 25 well data set provided the geologic foundation for the Project ECO₂S CO₂ Storage Complex.

2.  Establishing the Presence of Sufficient CO₂ Storage Capacity.  The GSA study provided a preliminary CO₂ storage capacity estimate of 4 to 5 MMmt per square mile for the Paluxy Sandstone implying a storage capacity of 200+ MMmt for the proposed CO₂ storage unit. Subsequently, Advanced Resources performed additional geologic work and constructed a series of geological cross-sections for the CO₂ storage site.  This confirmed that all three of the saline formations - - Paluxy, Washita-Fredericksburg, and Tuscaloosa Massive Sand - - are regionally extensive with considerable net sand thickness.  Using this information, the Project ECO₂S Team calculated a CO₂ storage capacity of 480 MMmt for all three formations at the proposed CO₂ storage site.

3. Performing Reservoir Modeling to Establish the Areal Extent of the CO₂ Plume.  Advanced Resources undertook reservoir modeling to: (1) better understand CO₂ injectivity, (2) calculate the areal extent of the CO₂ plume, and (3) provide a more rigorous estimate of CO₂ storage capacity in the Tuscaloosa Massive Sand, Washita-Fredericksburg and Paluxy.   Reservoir modeling showed that the 30,000 acre proposed CO₂ storage site had an overall CO₂ storage capacity of 300 MMmt and could readily accommodate the CO₂ plume from 3 MMmt/yr of CO₂ injection for 30 years, Exhibit 2.

4. Utilizing Data from Prior Deep Well Drilling.  To characterize the reservoir setting and establish a potential water source, MPC and SCS had previously drilled two wells - -  a small-diameter test well and a large-diameter water production well.  The small-diameter test well was drilled to 3,962 ft (below surface) through the Massive Sand of the Tuscaloosa Group.  A geophysical log suite was run in this well.  The large-diameter water production well was drilled to 3,442 ft (below surface) and completed in the Tuscaloosa Massive Sand.  A pumping test was conducted to quantify the flow potential of the Massive Sand. Water samples from the  Massive Sand indicated a Total Dissolved Solids (TDS) of 23,000 mg/L (ppm), establishing that the water was non-potable.

5.  Establishing the Availability and Reliability of the CO₂ Source.  The Kemper energy facility, with CO₂ output of about 3 MMmt per year, will be the source of the CO₂.  Because a $141 million, 61-mile pipeline for transporting CO₂ already exists, Project ECO₂S only needs short distance gathering lines for connecting the CO₂ source with CO₂ injection wells at the storage site.

6. Securing Surface and Pore Space Rights. The proposed CO₂ storage area would encompass a ~30,000 acre area in Kemper County. As part of defining and securing the proposed CO₂ storage site, MPC (with assistance from the modeling work performed by Advanced Resources) identified the Area of Interest (AOI).  MPC also defined the protected and environmentally sensitive areas near the proposed well sites, and already owns surface and pore space rights in the center of the CO₂ storage area.

7. Conducting Initial Stakeholder Reviews and Economic Analyses.  MPC had already conducted extensive stakeholder analysis in the communities near the CO₂ storage site associated with the permitting and construction of the Kemper County energy facility.  With participation of Advanced Resources, SCS prepared preliminary capital and operating costs for commercial-scale CO₂ storage at the ECO₂S CO₂ Storage Complex.