Drilling fluid and method
US4299710A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 1975 |
| Grant date | Nov 10, 1981 |
| Priority date | — |
| Expiry date | May 30, 1995 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L3/00
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The application discloses a viscous aqueous alkaline drilling liquid (fluid) essentially free of clays, for drilling subterranean wells, and a method of drilling such wells. The fluid is circulated into and out of the well, to flush out drill cuttings. The alkaline composition comprises a combination of the thickeners (a) 10 to 90 parts by weight of an addition polymer of an unsaturated carboxylic acid, preferably in the form of a copolymer with another ethylenically unsaturated monomer, for example a copolymer of a major amount of methacrylic acid and a minor amount of ethyl acrylate, the polymer having a molecular weight of from 125,000 to 12,000,000 solubilized in the aqueous system by an alkali such as sodium carbonate, and (b) 10 to 90 parts by weight of a water soluble polysaccharide, or a water soluble derivative thereof ("polysaccharide" being used herein in a generic sense to include such derivatives) such as hydroxyethyl cellulose, the total amount of (a) plus (b) being 100 parts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.