Self-breaking viscous aqueous solutions and the use thereof in fracturing subterranean formations
US3960736A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 1974 |
| Grant date | Jun 1, 1976 |
| Priority date | — |
| Expiry date | Jun 3, 1994 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S507/922
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Viscous aqueous solutions are prepared which maintain a certain viscosity range over a predetermined period of time (i.e., induction period) and which thereafter break, i.e., decrease in viscosity over a very short period of time. The viscous aqueous solution comprises a polysaccharide having an ability to thicken water and dispersed or dissolved in the aqueous solution an effective quantity of an organic ester which, at a temperature at which it is desired to break the viscous solution, hydrolyzes over a delayed period of time to form an acid which degrades the polysaccharide, thus causing a splitting of the polysaccharide chain and a decrease in the viscosity of the solution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.