Environment-friendly water-based drilling fluid applicable to horizontal shale gas wells
US9783726B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 17, 2017 |
| Grant date | Oct 10, 2017 |
| Priority date | — |
| Expiry date | Apr 17, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K2208/12
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The present invention relates to the well drilling field in petrochemical industry, and discloses an environment-friendly water-based drilling fluid applicable to horizontal shale gas wells comprising a nano-plugging agent, a bionic wall bracing agent, a bionic shale inhibitor, a filler, an emulsifier, and an amphiphobic wettability reversal agent, wherein, the nano-plugging agent is modified silicon dioxide nano-particle, and its modifying group includes an acrylic copolymer chain; the bionic wall bracing agent is carboxymethyl chitosan with a dopamine-derived group grafted on its main chain; the bionic shale inhibitor is composed of structural units of arginine and structural units of lysine; the filler consists of calcium carbonate of 1,600-2,500 mesh, calcium carbonate of 1,050-1,500 mesh, and calcium carbonate of 500-1,000 mesh at a weight ratio of 1:0.55-6:0.55-6; and the amphiphobic wettability reversal agent is a dual-cation fluorocarbon surfactant. The drilling fluid provided in the present invention has high temperature-resistance, high plugging and high inhibition performance, is environment friendly, especially has high density, and is applicable to shale gas mining.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.