The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 29, 2025
Filed:
Mar. 05, 2025
Southwest Petroleum University, Chengdu, CN;
Southwest Petroleum University, Chengdu, CN;
Abstract
Disclosed are a strong salt-resistant self-degradation plugging agent for water-based drilling fluid and a preparation method therefor. The preparation method includes: modifying unsaturated polyhydroxyalkanoate by using 2-acrylamide-2-methylpropanesulfonic acid to prepare modified polyhydroxyalkanoate; modifying lignin by using an ammonium halide salt to prepare quaternized lignin; and melting and blending the quaternized lignin and the modified polyhydroxyalkanoate to obtain the strong salt-resistant self-degradation plugging agent for water-based drilling fluid. The preparation method is mature and reliable, and is suitable for industrial production. The plugging agent has strong salt resistance and good stability, and has a degradation rate less than 15% within 7 days, which can effectively plug micron-sized fractures in shale formations. Meanwhile, the plugging agent may be directly added to the water-based drilling fluid, and has little effect on the rheology. With addition of the plugging agent, the high-temperature and high-pressure filtration loss of the drilling fluid is significantly reduced.