Impact of karstification in trapping mechanisms of CO2 storage

A carbonate-depleted carbonate gas field located offshore Sarawak has been identified as potential candidate for CO2 sequestration site in conjunction with another high CO2 gas field development for commercialization efforts. The field has undergone a feasibility study to evaluate potential geochemical reactions specifically on trapping mechanisms and storage capacity associated with CO2 injection. A detail 3D reactive transport modelling study was conducted to quantify on the four different trapping mechanism: structural, residual, solubility, and mineral trapping during and post-injection. The model was developed by first converted the available field history matched black oil simulation model into compositional 3D model, in which CO2 is treated as separate component in the reservoir through the production and injection processes. The study covered 22 years of gas production history forecast followed by 27 years of injection and 1000 years of post-CO2 injection in the gas column reservoir. The results show that the field has potential to store and sequestrate CO2 up to for 79% structural trapping, 19% residual trapping, 3% solubility trapping and no mineral trapping after 1000 years of post-injection period.

Automated summary

The carbonate-depleted carbonate gas field off the coast of Sarawak has been identified as a potential candidate for CO2 sequestration, with a feasibility study showing high potential for storing and sequestering CO2. Through detailed modeling, it was found that the field has a high proportion of structural trapping and residual trapping mechanisms.