Abstract: The amount of a petroleum recovery chemical retained within a subterranean reservoir is predicted by first gathering data from at least one injection-soak-production cycle in a core wherein the produced fluids are monitored for both the chemical concentration in the produced fluid as well as the concentration of a nonabsorbing tracer and, second, utilizing this data in a chemical flood mathematical model to simulate at least one repetition of the injection-soak-production cycle. The simulated cycles are repeated until the simulated produced fluid concentration of the chemical is virtually the same as the actual produced fluid concentration of the nonabsorbed tracer. The amount of the chemical retained per unit of reservoir volume is then determined by conventional techniques.

Abstract: The amount of a petroleum recovery chemical retained within a subterranean reservoir is predicted by first gathering data from at least one injection-soak-production cycle in a single well wherein the produced fluids are monitored for both the chemical concentration in the produced fluid as well as the concentration of a nonabsorbing tracer and, second, utilizing this data in a chemical flood mathematical model to simulate at least one repetition of the injection-soak-production cycle. The simulated cycles are repeated until the simulated produced fluid concentration of the chemical is virtually the same as the actual produced fluid concentration of the nonabsorbed tracer. The amount of the chemical retained per unit of reservoir volume is then determined by conventional techniques.

Abstract: The efficiency of a low tension surfactant flooding program is improved by first determining the upper and lower boundaries for the range of injected water salinities, that, when intermingled with the injected aqueous surfactant slug will enable the surfactant to resist partitioning into an oil and/or emulsion phase and thereby continue to operate with maximum effectiveness. The water in the driving slug is formulated to fall within the specified salinity boundaries and is then injected at the appropriate time in the sequence of steps in the oil recovery operation.

Abstract: In a subterranean reservoir containing both petroleum and water interspersed, the petroleum may be preferentially produced by injecting into one well penetrating the reservoir a slug of fluid comprising hydrocarbon solvent, colloidal silica, water and a polymeric material followed by a driving fluid comprising water to force the reservoir fluids into another well penetrating the reservoir where they are produced.