Toe-to-heel oil recovery process
US6167966A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 4, 1998 |
| Grant date | Jan 2, 2001 |
| Priority date | — |
| Expiry date | Sep 4, 2018 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B43/305
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
In an underground oil reservoir, an injection well is completed low in the reservoir and a production well is provided having a horizontal leg completed relatively high in the reservoir and a vertical leg completed low in the reservoir. Water is injected with the vertical leg open and the horizontal leg closed, so that a displacement front advances in an under-riding manner between the wells and oil is produced through the vertical leg. Once the water break-through in the vertical leg occurs, it is closed and the horizontal leg is opened. A rising, horizontal, gravity-stable displacement front then advances upwardly toward the horizontal leg, through which oil is produced. The open horizontal leg acts as a low pressure sink to induce the horizontal displacement front to advance up toward it. This two-stage process is characterized by a good vertical and lateral sweep. In a slightly modified version, water is injected with the vertical leg closed and the horizontal leg open so that a gravity-stable displacement front advances both laterally and vertically with a relatively upright position of a displacement front. In this version (one stage process) the process is also characterized…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.