Evaluating storage and leakage scenarios for carbo n dioxide sequestration in Trinidad and Tobago

Abstract Trinidad and Tobago (T&T), being part of the United Nations and heading towards deve loped status thanks to very large natural gas reserves and associated energy -intensive industry (cement, methanol, LNG etc), will eventually have to control their greenhouse gas emissions. The last inventory of current emissions in T&T indicates that stor age within T&T is feasible but will require careful design of storage schemes. In T&T, this CO 2 can be strategically placed in deep saline aquifers and depleted oil and gas reservoirs. Faults and sands in the area have been reasonably well characterized for oil and gas exploration. Coincidentally the islands have several surface seeps of hydrocarbons, some of which are associated with leakage from deeper reservoirs. T&T is thus a convenient natural laboratory for evaluating storage options and the potential for leakage of stored CO 2 . This paper presents a preliminary case study on the Mahogany field which is owned by British Petroleum (bpTT). This field is located 60 miles offshore from the southeast coast of Trinidad and comprises a series of stacked gas sands in seven separate major fault blocks. The potential for leakage of the sequestered CO 2 from these faults was studied to quantify possible fluxes and migration pathways in this geologic environment using the CMG–GEM reservoir simulation software.