Method and apparatus for riserless drilling
US7150324B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 2002 |
| Grant date | Dec 19, 2006 |
| Priority date | — |
| Expiry date | Oct 4, 2022 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B7/128
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An offshore riserless drilling system drills a subsea borehole from a platform and through a cased borehole. The system comprises a lightweight drill string suspending a bottomhole assembly and extending from the platform downwardly through a depth of water into the cased borehole; a first limiter limiting the range of motion of the drill string adjacent the platform; and a second limiter limiting the range of motion of the drill string adjacent the cased borehole. The preferred methods include lowering a bottomhole assembly suspended on a lightweight drill string from a platform through a depth of water; limiting the bend radius of the drill string adjacent the platform; guiding the bottomhole assembly into a cased borehole; limiting the bend radius of the drill string adjacent the cased borehole; maintaining the bottomhole assembly in the cased borehole, and drilling the subsea borehole.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.