Ester based invert emulsion drilling fluids and muds having negative alkalinity
US5977031A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 7, 1998 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Aug 7, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S507/933
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
An invert emulsion suitable for drilling subterranean wells, in particular oil and gas wells is disclosed which includes an oleaginous phase, and a non-oleaginous phase and a protonated amine surfactant which stabilizes the invert emulsion in the absence of an alkaline reserve material. The protonated amine surfactant has the general formula: EQU [R--N.sup.+ --H.sub.3 ]B.sup.- wherein R is a C.sub.12 to C.sub.22 alkyl group and B.sup.- is a conjugate base of an acid; and the protonated amine surfactant is present in an amount capable of stabilizing the invert emulsion in the absence of an alkali reserve. The practice of the present invention permits the use of a broad range of esters as the oleaginous phase including simple alkyl esters which previously susceptible to hydrolysis due to the presence of an alkaline reserve material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.