Production process for manufacturing low molecular weight water soluble acrylic polymers as drilling fluid additives
US4794140A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 30, 1987 |
| Grant date | Dec 27, 1988 |
| Priority date | — |
| Expiry date | Nov 30, 2007 |
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 crosslinking 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.