US 10,889,742 B1
Modified polyhistidine suitable for being used as a supramolecular shale inhibitor, method of preparing the same and its application in water-based drilling fluids
Guancheng Jiang, Beijing (CN); Yinbo He, Beijing (CN); Lili Yang, Beijing (CN); Kai Wang, Beijing (CN); Tengfei Dong, Beijing (CN); Xiaohu Quan, Beijing (CN); Kaixiao Cui, Beijing (CN); and He Shi, Beijing (CN)
Assigned to CHINA UNIVERSITY OF PETROLEUM (BEIJING), Beijing (CN); and BEIJING SHIDA BOCHENG TECHNOLOGY CO., LTD, Beijing (CN)
Filed by CHINA UNIVERSITY OF PETROLEUM (BEIJING), Beijing (CN); and Beijing Shida Bocheng Technology Co., Ltd, Beijing (CN)
Filed on May 29, 2020, as Appl. No. 16/887,869.
Int. Cl. C09K 8/035 (2006.01); C08G 69/48 (2006.01); C09K 8/05 (2006.01)
CPC C09K 8/035 (2013.01) [C08G 69/48 (2013.01); C09K 8/05 (2013.01); C08G 2261/72 (2013.01)] 10 Claims
 
1. A modified polyhistidine suitable for being used as a supramolecular shale inhibitor, wherein the modified polyhistidine has a histidine polymerization main chain comprising a structural unit, which is represented by Formula (1) and attached with a modifying group;
the histidine polymerization main chain has a histidine polymerization degree of 7-8;

OG Complex Work Unit Drawing
each R1 is independently selected from the group consisting of methyl, ethyl, n-propyl, isopropyl and n-butyl; X is Cl, Br or I; R2 is selected from the group consisting of —CH2—CH(OH)—CH2—, —CH2—CH2—CH(OH)—, —CH(OH)—CH2—CH2—, —CH2—CH2—CH(OH)—CH2—, —CH2—CH(OH)—CH2—CH2— or —CH2—CH2—CH(OH)—CH2—CH2—;
the content of the structural unit represented by Formula (1) is 20 mol % or more.