Method and system for displacing drilling fluid from a drill string in a well drilling system
US4577700A · kind A · utility
11Cited by
6References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 16, 1984 |
| Grant date | Mar 25, 1986 |
| Priority date | — |
| Expiry date | Apr 16, 2004 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B21/01
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A rotary well drilling system employs a drill string with a drill bit affixed at its lower end for the drilling of a borehole. Drilling fluid is circulated through the drill string to remove drill cuttings. To break out a section of drill pipe from the drill string, the drill string is raised to a point where the drill string joint to be broken is above the drilling rig floor. Compressed gas is injected into the drill string to displace the column of drilling fluid to a level below such drill string joint. The compressed gas is vented and the drill pipe is broken out of the drill string.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.