Amphiphilic block polymer ultralow-permeability agent and intelligent temporary plugging type water-based drilling fluid
US11578251B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 2022 |
| Grant date | Feb 14, 2023 |
| Priority date | — |
| Expiry date | Mar 16, 2042 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F2438/03
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The invention relates to the technical field of oil and gas drilling, and discloses an amphiphilic block polymer ultralow-permeability agent and an intelligent temporary plugging type water-based drilling fluid. The ultralow-permeability agent contains a structural unit provided by styryl hydrophobic monomer, maleic anhydride and acrylamide; the drilling fluid contains two or more of water, sodium bentonite, Pac-Lv, the ultralow-permeability agent, calcium carbonate, one-way plugging agent, white asphalt and barite which are stored in a mixed manner or independently stored. When the amphiphilic block polymer provided by the invention is used as the ultralow-permeability agent of the intelligent temporary plugging type water-based drilling fluid, the self-adaptive characteristic is realized; according to the amphiphilic block polymer, temporary plugging layer gaps formed in pore and throats by plugging materials in drilling fluid can be fully filled under the condition that the sizes and the distribution of the pore and throats of reservoirs are not required to be clear, so that the permeability of temporary plugging layer is greatly reduced, ultralow-permeability is realized, and t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.