Abstract: A method for determining the injection source of an injection fluid which will break through at the production wells of a subterranean flooding project is disclosed in the preferred embodiment. The source of the injection fluid is determined by injecting halocarbon tracer compounds into the fluid stream injected into the subterranean formation. The tracer compounds of the injection are identified by gas chromatography/electron capture detection analysis.

Abstract: A process for the recovery of oil from a subterranean formation containing oil, which is preferably a residium from a prior recovery operation which comprises injecting into said formation a first treatment fluid comprising an aqueous solution of polymer of 50 ppm to 5000 ppm polymer, for example a partially hydrolyzed polyacrylamide, in an amount of from 0.5 to 100% pore volume of the formation and thereafter injecting into said formation a second treatment fluid comprising a mixture of an aqueous solution of polymer and from 0.01 to 3.5 weight percent caustic, for example NaOH, in an amount of from 0.5 to 100% pore volume of the formation and recovering oil from the formation.