Pressure relief process for well-drilling
US4852667A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 26, 1987 |
| Grant date | Aug 1, 1989 |
| Priority date | — |
| Expiry date | Jun 26, 2007 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B41/0078
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A drill string has a bulge equipped with a system of n injection ducts connecting the interior of the string surrounding annular space and opening upwardly into the space to divert a part of the drilling fluid supplied to the bit. This arrangement makes it possible to produce below the bulge a pressure decrease H markedly greater than 10 meters of water by setting the flow of drilling fluid in the system of injection ducts at a value, expressed in m.sup.3 /s, equal to approximately: .sqroot.10H.times.S.times.s33 n, S and s being the cross-sections, expressed in m.sup.2, respectively, of a part of the portion of the annular space included between the periphery of the bulge and the drill string and of the group of n injection ducts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.