Use of CO.sub.2 /steam to enhance floods in horizontal wellbores
US4982786A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 14, 1989 |
| Grant date | Jan 8, 1991 |
| Priority date | — |
| Expiry date | Jul 14, 2009 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B43/305
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method to enhance steam flooding where at least two horizontal wellbores are utilized. Carbon dioxide is injected into a lower perforated horizontal wellbore. Once sufficient carbon dioxide has been injected into the formation, steam is injected through the lower horizontal wellbore. The steam displaces the carbon dioxide into the formation where it contacts and mixes with hydrocarbonaceous fluids. Steam causes the carbon dioxide to expand, thereby providing for a better sweep of the formation. Steam injection is ceased and liquid carbon dioxide injection again is commenced. Afterwards, steam is injected again into the formation. This sequence is continued until it becomes uneconomical to produce hydrocarbonaceous fluids from an upper horizontal wellbore. Hydrocarbon displacement efficiencies are enhanced when hydrocarbons are produced into the upper horizontal wellbore due to viscosity and density differences.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.