Acid coated sand for gravel pack and filter cake clean-up
US6817414B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 20, 2002 |
| Grant date | Nov 16, 2004 |
| Priority date | — |
| Expiry date | Sep 20, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S507/924
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method of the preparation and utilization of polymerized alpha-hydroxycarboxylic-acid-coated proppants for gravel pack and removal of filter cake that was deposited by reservoir drilling fluid. In a preferred example, polyglycolic-acid-coated sand is used to replace conventional gravel pack sand typically used for gravel packing. Under downhole conditions, the acidic by-product generated from the hydration of polyglycolic-acid-coated sand can break down acid-soluble and/or acid-breakable components embedded in the filter cake. This reaction enhances the filter cake removal and the flow of hydrocarbon from the producing formation. The polyglycolic-acid-coated sand may be produced by polymerizing a glycolic acid with a natural or synthetic proppant like 20-40 mesh commercial sand, at temperatures of about 210° F. or higher.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.