Oil-based drilling fluid
US5888944A · kind A · utility
46Cited by
21References
27Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 23, 1997 |
| Grant date | Mar 30, 1999 |
| Priority date | — |
| Expiry date | Jun 23, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K2208/18
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method of removing the filter cake formed from invert emulsion compositions including an oleaginous, a non-oleaginous and an acid sensitive surfactant in an oil and gas well are disclosed. The acid sensitive surfactant is selected so that the invert emulsion can be broken and residual filter cake solids made water-wet upon the addition of an acidic wash fluid to the well.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.