Method for plugging lost circulation areas and lost circulation material to be used therefor
US4958685A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 1989 |
| Grant date | Sep 25, 1990 |
| Priority date | — |
| Expiry date | May 24, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K8/502
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method for plugging the areas of lost circulation occurred during the drilling of a well with the use of a drilling mud, and a lost circulation material to be used therefor. The lost circulation material comprising 1 to 90 parts by weight of a water-soluble solvent containing no active hydrogen atoms and hardly miscible with mineral oils and 10 to 99 parts by weight of a hydrophlic urethane prepolymer, and the method comprises injecting through the drilling pipe the lost circulation material sandwiched by a spacer of mineral oils, so as to allow the lost circulation material to penetrate into the lost circulation areas, to react with water which is present at the areas, and to plug the areas through its polymerization.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.