Thirty (30) Years of Steamflooding: Reservoir Management and Operational Experiences

Abstract The Petroleum Company of Trinidad and Tobago Limited (Petrotrin) has a heavy oil reserves base of 300 million barrels of heavy oil in the southern part of the island of Trinidad. The Company, and its predecessors, first embarked on a thermal recovery program in its acreage from 1963 with cyclic/steamflooding operations. At the present time, the Company is operating eleven (11) steamfloods and is currently implementing another major project. This paper presents a case history of the Company's thirty-two years experience in steamflooding, inclusive of reservoir management and monitoring methods, innovations and operating practices. To date (1995 June), the Company has recovered a total of 77 million barrels of heavy oil from its acreage, with a current production level of 9000 BOPD. During this period, new diagnostic methods were initiated, as well as new innovations. These include cluster drilling, slim-hole injectors, insulated tubing and packers, non-gravel packed injectors, high volume pumps, limited entry perforating, insulated casing completions, diverting agents, dual injectors, iso-fluid mapping and other reservoir management techniques. In summary, the Company has had extensive success in steamflooding operations and continues to utilise this method for exploitation of its heavy oil reserves. With its proven success and existing infrastructure for this type of operation, the Company still has major opportunities in heavy oil recovery. Additionally, new methods of operation, financing and project management are being pursued to exploit these reserves. Based on Trinidad's complex geology and heterogeneous reservoirs, heavy oil recovery has been a major success through the Company's scope of operations. Several innovations in reservoir management and operating strategies can be implemented in other similarly adverse environments for heavy oil recovery.