From Imagination to Reality: Case Study of an Appraisal Well For CO2 Sequestration Project in Malaysia

In Malaysia, more than 70% reserves are held within carbonate reservoir with more than 13TcF of hydrocarbon gas locked in high CO2 fields. With that PETRONAS are embarking journey to unlock and monetize the high CO2 gas fields via CO2 sequestration project with the aim to separate CO2 and store CO2 underground thru pilot project in Field A. Field A is unique in several aspects whereby it has 70% CO2 and 30% of potential hydrocarbon gas sale which is equivalent to approximately 700 million tons of CO2 to be stored and would be the biggest CO2 sequestration project recorded in industrial. The geological storage site will also be within the same field which is located in deep seated aquifer below the producing reservoir. An appraisal well was successfully drilled in Field A with specific well objectives designed to address critical factors identified in CO2 sequestration project ranging from surface to subsurface. The well recorded several key highlights en route, among others, Malaysia’s first cap rock mini fracture test and first water injectivity test in aquifer interval, PETRONAS longest continuous carbonate coring and first cap rock shale core with 98% and 100% core recovery respectively. The cores data is crucial to de-risking initial GIIP and to update current geological model for further evaluation on A5 field as CO2 storage potential sequestration sites