Method for removing drill cuttings from wellbores and drilling fluids
US6794340B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 2002 |
| Grant date | Sep 21, 2004 |
| Priority date | — |
| Expiry date | Feb 15, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S507/903
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method is disclosed for drilling a wellbore employing a drilling fluid providing the advantages of easy pumpability of a low viscosity fluid with the drill cuttings suspension capability of a highly viscous fluid. The viscosity of the fluid is also easily and quickly adjustable so that the fluid rheology may be adapted during drilling as the subterranean conditions change. These advantages are obtained by including in said fluid a reversibly crosslinkable polymer and an encapsulated crosslink activator. The crosslink activator causes crosslinking after the fluid is in the wellbore. The crosslinking is reversed at the well surface to reduce the viscosity of the fluid to enable the drill cuttings to be easily removed. Crosslink activator is added back to the fluid and the fluid is returned to the borehole. The amount of crosslink activator and/or crosslinkable polymer may be adjusted in the fluid to change the fluid rheology to conform the fluid to changes in the well conditions as monitored real time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.