High conformance oil recovery process
US4159037A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 1, 1978 |
| Grant date | Jun 26, 1979 |
| Priority date | — |
| Expiry date | May 1, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K8/584
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The conformance of an enhanced oil recovery process, including waterflood, surfactant or other chemicalized water flood process, in a formation containing at least two strata or zones of varying permeability, the permeability of one zone being at least 50 percent greater than the permeability of the other zone, is improved by flooding until the higher permeability zone has been depleted, after which an aqueous fluid is injected into the high permeability zone, said fluid having relatively low viscosity at the time of injection and containing a blend of surface active agents which promote the formation of a coarse viscous emulsion in the flow channels of the formation which reduces the permeability of the high permeability zone. After the permeability of the first zone has been reduced substantially, flooding may then be accomplished in the second zone which was originally not invaded by the injected oil recovery fluid. The surface active agents are individually tailored and the ratio of dissimilar surfactants balanced to exhibit optimum viscous emulsion formation properties. The optimum emulsifying surfactant comprises a mixture of an organic sulfonate such as petroleum sulfonate a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.