Status and Assessment of Chemical Oil Recovery Methods

Over two-thirds of the original oil remains unrecovered in an oil reservoir, after primary and secondary recovery methods have been exhausted. Many chemically based oil recovery methods have been proposed and tested in the laboratory and field. Indeed, chemical oil recovery methods offer a real challenge in view of their success in the laboratory and lack of success in the field. The problem lies in the inadequacy of laboratory experiments on one hand, and the very limited knowledge of the reservoir characteristics on the other. Field test performances of polymer, alkaline, and micellar flooding methods are examined for nearly 50 field tests, results for which are tabulated. The oil recovery performance of micellar floods is the highest, followed by polymer floods. Alkaline floods have been largely unsuccessful. The reasons underlying success or failure are examined.