Additive composition suitable for viscosity reduction of oil-based drilling fluid, oil-based drilling fluid and use thereof
US9745501B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 2017 |
| Grant date | Aug 29, 2017 |
| Priority date | — |
| Expiry date | Mar 22, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K2208/34
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The present invention relates to the well drilling field in petroleum industry, in particular to an additive composition suitable for viscosity reduction of oil-based drilling fluids, an oil-based drilling fluid and use thereof. The double-block copolymer mainly consists of a block A and a block B, wherein, the block A is composed of structural units represented by formula (1), the block B is composed of structural units represented by formula (2), and the number-average molecular weight of the block A is 1,500-10,000. The double-block copolymer provided in the present invention can be used as a viscosity reducer in oil-based drilling fluids, especially can be used as a viscosity reducer in high-density clay-free oil-based drilling fluids, and can greatly decrease the apparent viscosity and plastic viscosity of oil-based drilling fluids in high-temperature and high-pressure reservoir while maintaining appropriate shearing force, so as to increase the drilling rate and reduce drilling difficulties.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.