Drilling fluids containing AMPS, acrylic acid, itaconic acid polymer
US4699225A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 7, 1985 |
| Grant date | Oct 13, 1987 |
| Priority date | — |
| Expiry date | Nov 7, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K8/12
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Polymers of (1) from about 5% to about 50% by weight of 2-acrylamido-2-methylpropane sulfonic acid and (2) from about 95% to about 50% by weight of a second component, there being from 100% to about 80% by weight acrylic acid and from 0% to about 20% by weight of itaconic acid in the second component and having a weight average molecular weight of between about 50,000 to about 1,000,000 and which are at least water dispersible are used as fluid loss control additives for aqueous drilling fluids and are particularly advantageous when used with muds containing soluble calcium ions and muds containing chloride ions such as seawater muds. An example is a copolymer of 10% by weight 2-acrylamido-2-methylpropane sulfonic acid and 90% by weight acrylic acid in its sodium salt form.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.