Patent number: 9790417
Abstract: The present invention relates to the well drilling field in petrochemical industry, and discloses a high-density water-based drilling fluid suitable for 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 a modifying 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.
Type:
Grant
Filed:
April 17, 2017
Date of Patent:
October 17, 2017
Assignee:
China University of Petroleum (Beijing)
Inventors:
Guancheng Jiang, Yinbo He, Fan Liu, Lili Yang, Xianmin Zhang, Deli Gao, Xianzhu Wu, Guangchang Ma, Gang Qu, Li Zhao, Haifang Sun, Wei Ou'yang, Junbin Chen, Jienian Yan, Liexiang Han, Chunyao Peng