Preliminary assessments of CO2 storage in carbonate formations: a case study from Malaysia

The preliminary assessment of depleted reservoirs prior to the injection of CO2 is an essential step to ensure the safety and success of storage projects. Several studies have provided a preliminary assessment of depleted reservoirs as a sequestration practice. However, the screening criteria used in these studies were not able to consider all of the aspects of a storage site. The aim of this paper is to provide a reservoir-scale evaluation approach for long-term storage practice in an offshore carbonate field located in Malaysia. Recently developed screening criteria that cover the key aspects of storage sites, such as capacity, injectivity, trapping mechanisms, and containment, are taken into consideration for the purpose of this study. The results obtained suggest that the reservoir has good potential to be a storage place for CO2, although the compaction behavior and aquifer supports of the reservoir might cause some difficulties. It is, therefore, recommended that a series of experimental and numerical studies on different aspects of storage sites be performed to ensure that injectivity is not a problem when it comes to the implementation stage.