High pressure gas-carbonated water miscible displacement process

Abstract

Abstract Reservoir oil is produced by a quasi high pressure gas miscible solvent flood process. Immiscible carbonated water flow through the reservoir in essentially a single phase at an appropriate concentration and pressure leaves a widespread, fairly uniform distribution of carbonated residual oil which acts as a quasi solvent material. Subsequently, a fluid containing a gaseous phase is injected at a miscible pressure below the pressure at which the gas would have built miscibility with the reservoir oil prior to carbonation but high enough to possibly create by multiple contacts a zone miscible with the carbonated residual oil. The created miscible zone banks up the carbonated residual oil into a quasi miscible solvent flood bank. Preferably, the highest pressure exerted on the carbonated water will be equal to or greater than the miscible pressure of the gas, and the injection pressure of the gas will be at least 200 psi higher than highest injection pressure exerted on the carbonated water. An aqueous phase, part of which may be carbonated water, may be used with the miscible gas for mobility and other controls. In the process, the quasi solvent material is generated in place with the mobility and uniform sweep advantages of carbonated water, and the high pressure type of miscibility is created at a lower than normal pressure and banks up a carbonated oil solvent bank thereby providing some of the advantages of the miscible solvent flood process.

Inventors

• 👤 L Kern

Bibliographic Details