Addressing the Complexities of Establishing a Comprehensive CO2 Storage Hub in the Large-Scale Saline Aquifer Offshore Malaysia

Abstract The rising CO2 emissions resulting from the development of high CO2 contaminated gas fields in Malaysia necessitate the identification of appropriate, secure, and capacious reservoirs for CO2 storage. Large-scale saline aquifers have emerged as promising solutions for establishing a storage hub equipped with extensive onshore injection facilities. Nevertheless, the development of a large-scale saline aquifer as a CO2 storage hub offshore Malaysia presents numerous intrinsic challenges. The current study focusses on identifying and evaluating the associated risks and uncertainties and formulating a mitigation strategy for the development of a large-scale storage hub within synrift sediments of a rift graben off the coast of peninsular Malaysia (PM). When establishing a large-scale CO2 storage hub, it's crucial to prioritize two key elements: containment integrity and storage capacity. However, these components carry inherent risks that demand careful management throughout the storage development process. Containment integrity entails risks related to reservoir and overburden formations, structural features, and well integrity within the storage reservoirs. Conversely, storage capacity can be influenced by factors like reservoir continuity, aquifer size and strength, caprock strength, and injectivity. The storage site was analyzed for its containment and capacity through extensive 3D data interpretation for generation of structural maps, mapping of major and minor faults, and attribute extraction, trap & seal analysis, faults & wells integrity analysis, 1D caprock integrity analysis, and effective storage capacity estimation through dynamic simulation. Dynamic simulation results of maximum storage capacity help deciding plausible mitigation plans, such as seismic data acquisition, appraisal well drilling, and coring, have been suggested to tackle these risks. However, quantifying the precise value added by these plans in terms of risk reduction presents a challenge. The workflow for this study to be used as the guideline for any future saline aquifer storage development plan feasibility study.