Underbalance jet pump drilling method
US5355967A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 1992 |
| Grant date | Oct 18, 1994 |
| Priority date | — |
| Expiry date | Oct 30, 2012 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B21/085
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method for rotary drilling and removing cuttings provides a underbalanced drilling fluid pressure at the drilling face but overbalanced pressure in the wellbore. The preferred method uses a rotary drill within a housing which also encloses a jet pump which draws and pressurizes the cuttings and drilling fluid, a separator of the cuttings and a portion of the pressurized drilling fluid, and a nozzles to supply separated and reduced pressure drilling fluid back to drilling face while the cuttings and remaining pressurized drilling fluid flows up towards the surface. The method avoids overpressure strengthening of the drill face and underpressure damage to the wellbore.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.