High temperature drilling fluids
US4566978A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 21, 1984 |
| Grant date | Jan 28, 1986 |
| Priority date | — |
| Expiry date | May 21, 2004 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K8/24
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
An aqueous drilling fluid suitable for high-temperature use comprising a water base, clay suspended in said base and from about 0.01-25 pounds per barrel total composition of a hydrolyzed terpolymer of maleic anhydride, styrene and a third monomer selected from acrylamide, methacrylamide, acrylic acid or methacrylic acid, the molar ratio of maleic anhydride to styrene to said third monomer being from about 30:10:60 to 50:40:10, and the alkali metal, ammonium and lower aliphatic amine salts thereof, the weight-average molecular weight of said hydrolyzed terpolymer being from about 500-10,000. An improved drilling process wherein such fluids remain flowable at elevated temperatures is also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.