Production process for manufacturing low molecular weight water soluble acrylic polymers as drilling fluid additives
US4709767A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 6, 1986 |
| Grant date | Dec 1, 1987 |
| Priority date | — |
| Expiry date | Jan 6, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S524/916
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Disclosed is a process for preparing relatively low molecular weight, water absorbing, acrylic polymers for use as drilling fluid additives by aqueous polymerization of (A) an acrylic monomer, such as acrylic acid neutralized 0 to 100 mole percent with, for example, ammonia, and/or an alkali such as Na.sub.2 O.sub.3, and/or an amine; with (B) acrylamide in a mole ratio of 70 to 100 mole percent (A) to 30:0 mole percent (B). The molecular weight is limited to 1,000 to 50,000, such as by adding a chain transfer agent to the polymerization mixture, to achieve excellent results as a drilling fluid additive. The monomer, such as partially neutralized acrylic acid, is polymerized in aqueous solution in the presence of a polymerization initiator without external heating while allowing water to evaporate off. A substantially dry water soluble polymer (less than 15 weight percent water) is achieved when polymerization is completed by utilizing the exothermic heat of polymerization and cross-linking to drive off water without the need for additional heating to obtain a dry solid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.