Shale stabilizing drilling fluids comprising calcium chloride and low molecular weight low charge cationicpolyacrylamide copolymers
US6355600B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 1, 1999 |
| Grant date | Mar 12, 2002 |
| Priority date | — |
| Expiry date | Oct 1, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K2208/18
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A drilling fluid and method of using same. The drilling fluid comprises water as a continuous phase, an amount of calcium chloride, and a quantity of a polyacrylamide copolymer. The amount of calcium chloride and the quantity of polyacrylamide copolymer in the drilling fluid are sufficient to produce a rate of penetration approaching that achieved using a synthetic oil-based drilling fluid while preventing substantial screen blinding. In a preferred embodiment, the continuous phase also comprises a second amount of a monovalent salt effective to increase gas hydrate suppression and decrease density when compared to a fluid consisting essentially of only a divalent salt in the absence of the monovalent salt.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.