(147b) Planning the First South African Pilot CO2 Storage Project

The South Africa Pilot CO₂ Storage Project (PCSP) is being executed by the South African National Energy Development Institute (SANEDI) with co-funding from the World Bank CCS Trust Fund. The development of CO₂ storage options in South Africa is a high priority due to its heavy reliance on coal as the primary energy source. The main objectives of the PCSP are to carry out a small-scale CO₂ injection, storage, and monitoring program; increase the South African human and technical capacity for CO₂ storage; raise awareness of potential importance of Carbon Capture and Storage (CCS); and work with the South African government to ensure the development and operations within the country’s legal and regulatory environment. The selected location for the PCSP is a Mesozoic-age sedimentary basin, the Zululand Basin, developed along the northeastern coastline of KwaZulu-Natal. Battelle has been providing the Project Technical Advisory Services (PTAS1) for the project, with the Phase I goal of identification of candidate storage sites within the basin and their screening for CO₂ storage potential. The research is being conducted with active technical participation from the South Africa Council for Geological Science and the Petroleum Agency of South Africa.

The PTAS1 team has performed extensive characterization analyses of the available 1960’s-1970’s subsurface data in the Zululand basin. While interpretation of existing 2D seismic, aeromagnetic, well log, and core data supplemented by new sampling of the legacy core and new sequence-stratigraphic interpretations has greatly increased the geologic understanding of the basin, the analyses indicate that the legacy data are insufficient to confidently site an injection well. Uncertainties remain regarding the petrophysical properties, architecture, behavior, and storage capacity of reservoirs and seals. To reduce these uncertainties, an exploration plan was developed to guide the acquisition of new data for the project. The exploration plan is designed to fill the data gaps and provide new data necessary for characterizing potential pilot CO₂ storage sites. Basin exploration activities include acquiring new, high-resolution aeromagnetic data, acquisition of nearly 300km of new, high-quality three-component seismic data, and the drilling of two new slim-hole characterization wells with complete coring and modern wireline logging. In parallel with field characterization planning, initial static and dynamic models are being prepared to evaluate the likely injectivity, capacity, and containment of CO₂ and to assist with project design.

The implementation of these exploration activities will result in new geophysical, petrophysical, geomechanical, and engineering data required for (1) the construction and population of static and dynamic earth models, (2) play identification and assessment and (3) ranking and risk analysis of play fairways and prospect leads. This will ultimately allow for selection of an appropriate location for drilling of the injection and monitoring wells for the pilot CO₂ storage project. This paper will present results of the data review, analysis, and initial modeling, along with the path forward to select the first CCS pilot test location in South Africa.