CO2 sequestration in oil reservoirs -: A monitoring and research opportunity

Construction is currently underway on a major project to capture and compress approximately 5000 tonnes per day Of CO2 from the Great Plains Synfuels Plant in North Dakota (USA). Additionally, construction of a 330 km pipeline to the Weyburn field in south-eastern Saskatchewan (Canada) is now complete. In August 2000, CO2 will be delivered to the field for injection into a mature oil reservoir. The project will be the largest CO2 enhanced oil recovery project in Canada when it commences operations. The Synfuels Plant, operated by Dakota Gasification Company, is the United States' first commercial size synthetic fuels plant based on coal conversion. Started in 1984, the plant currently converts 16200 tonnes of lignite coal daily into 3.54 million m(3) of pipeline quality synthetic natural gas, 900 tonnes of anhydrous ammonia, and other by-products. The intent has been to capture CO2 and make this an additional by-product stream for the plant. The Weyburn Field, operated by PanCanadian Petroleum Limited, was discovered in 1954. It has produced approximately 52 million in 3 of oil from primary and waterflood production and is currently in decline having produced in excess of 80% of the estimated recoverable reserves. Carbon dioxide enhanced recovery will add over 19 million in 3 of incremental oil and permanently sequester approximately 18 million net tonnes Of CO2. This paper will present an update on the development of this commercial enhanced oil recovery and CO2 sequestration project, discussing the issues surrounding the capture, transmission and distribution of the CO2 stream into the oil field. The paper will also discuss the proposed and completed data gathering exercise undertaken by PanCanadian to provide baseline information in advance of the commercial flooding of the field. The work undertaken in the field will provide the basis for a proposed multinational monitoring project that will examine in detail the short- and longterm fate Of CO2 in a mature oil field.