Abstract: A method for recovering oil from a subterranean formation penetrated by a well is provided, comprising the steps of injecting via the well a gas mixture into the formation, the gas mixture comprising carbon dioxide and a gas selected from the group consisting of methane, nitrogen, or mixtures thereof; wherein the gas mixture is injected in an amount sufficient to establish in the vicinity of the well a zone of oil in contact with the gas mixture; and wherein the carbon dioxide comprises about 5 percent to about 50 percent by volume at reservoir conditions of the gas mixture; shutting in the well for a predetermined period of time; and producing the well and recovering the residual oil from the formation.

Abstract: This invention is a new, novel method and apparatus for the measurement of fluid-fluid interfacial shear viscosities. The method and apparatus are simple in design and conducive to routine measurements. The viscosities are measured by observation of the unsteady state deformation of the interface after a slowly rotating cylindrical cell containing the sample is abruptly halted. The deformation is established with tracer particles located at the interface between the two fluids in the sample. Correlations show the relationship of the traversed angle of the particles to the interfacial shear viscosity, the viscosities and densities of the bulk phases, and the sample dimensions. The method is sufficiently sensitive to allow measurements of interfacial shear viscosities ranging from 0.001 to 5.0 surface poise depending on cell geometry and liquid viscosity.