Method and apparatus for injecting steam into a geological formation
US6708763B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 2002 |
| Grant date | Mar 23, 2004 |
| Priority date | — |
| Expiry date | Apr 30, 2022 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B43/24
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The present invention generally provides a method and apparatus for injecting a compressible fluid at a controlled flow rate into a geological formation at multiple zones of interest. In one aspect, the invention provides a tubing string with a pocket and a nozzle at each isolated zone. The nozzle permits a predetermined, controlled flow rate to be maintained at higher annulus to tubing pressure ratios. The nozzle includes a diffuser portion to recover lost steam pressure associated with critical flow as the steam exits the nozzle and enters a formation via perforations in wellbore casing. In another aspect, the invention ensures steam is injected into a formation in a predetermined proportion of water and vapor by providing a plurality of apertures between a tubing wall and a pocket. The apertures provide distribution of steam that maintains a relative mixture of water and vapor. In another aspect of the invention, a single source of steam is provided to multiple, separate wellbores using the nozzle of the invention to provide a controlled flow of steam to each wellbore.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.