US 12,269,985 B1
High density environmentally friendly polymer water-based drilling fluid with resistance to 240° C. and saturated salts, preparation method therefor and use thereof
Jinsheng Sun, Qingdao (CN); Jingping Liu, Qingdao (CN); Kaihe Lv, Qingdao (CN); Meichun Li, Qingdao (CN); Jiafeng Jin, Qingdao (CN); Jintang Wang, Qingdao (CN); Yuanwei Sun, Qingdao (CN); and Taifeng Zhang, Qingdao (CN)
Assigned to China University of Petroleum (East China), Qingdao (CN)
Filed by China University of Petroleum (East China), Qingdao (CN)
Filed on Nov. 19, 2024, as Appl. No. 18/951,901.
Claims priority of application No. 202411151885.5 (CN), filed on Aug. 21, 2024.
Int. Cl. C09K 8/24 (2006.01); C09K 8/508 (2006.01); C09K 8/512 (2006.01); E21B 21/06 (2006.01)
CPC C09K 8/24 (2013.01) [C09K 8/5086 (2013.01); C09K 8/512 (2013.01); E21B 21/062 (2013.01); C09K 2208/10 (2013.01)] 18 Claims
 
1. A water-based drilling fluid comprising a micro-crosslinked heterocyclic polymer filtrate reducer, a hyper-branched strongly adsorbed filtrate reducer, a nanometer intercalated complex shearing potentiator, a flexible outer and rigid inner microsphere plugging agent, and water, wherein the micro-crosslinked heterocyclic polymer filtrate reducer is prepared by reacting sodium p-styrene sulfonate, N,N,N-trimethyl-3-(2-methylallylamino)-1-propyl ammonium chloride, N,N-diethyl acrylamide, N-vinyl caprolactam, and tetramethyl ethylenediamine with phenyl triethoxy silane; the hyper-branched strongly adsorbed polymer filtrate reducer is prepared by reacting 2-acrylamido-2-methylpropanesulfonic acid, dimethyldiallyl ammonium chloride, 1-vinylimidazole, and a modified alkylene polyoxyethylene ether with a branching agent.