Carbon dioxide slug drive
Abstract
Abstract A slug drive to recover medium- to high-gravity petroleum from underground formations is carried out by injecting CO2 into the petroliferous formation. A typical amount used is of the order of 5 percent to 20 percent, say, 10 percent of the pore volume of the hydrocarbons present in the portion of the reservoir being treated. This CO2 is immediately followed by approximately an equal volume of air or flue gas, and then by water. Flue gas may be injected after or with the water. The gas immediately following the CO2 (flue gas or air) very effectively displaces the CO2 which is miscible with the petroleum of the reservoir. The following gas is both cheaper than the CO2 and serves as a protective bank, since the gas immediately ahead of the waterflood is to a degree trapped in passing through the reservoir. An additional benefit obtained by driving the CO2 bank with a gas (air or flue gas) less soluble in water is an improvement in mobility ratio, hence in sweep efficiency.
Inventors
- 👤 David R Parrish
Bibliographic Details
Claims Analysis
Total Claims: 5References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-21 | 1974-12-21 | 1975-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-21 | 1978-12-21 | 1979-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-21 | 1982-12-21 | 1983-06-22 | $7700.00 | Window Closed / Lapsed |