文献类型：期刊文献

英文题名：Performance of a New Thermostable Mannanase in Breaking Guar-Based Fracturing Fluids at High Temperatures with Little Premature Degradation

作者：Hu, Ke[1];Li, Chun-Xiu[1];Pan, Jiang[1];Ni, Yan[1];Zhang, Xiao-Yan[1];Xu, Jian-He[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Lab Biocatalysis & Synthet Biotechnol, Shanghai 200237, Peoples R China

年份：2014

卷号：172

期号：3

起止页码：1215

外文期刊名：APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY

收录：;EI(收录号：20141217496416);WOS:【SCI-EXPANDED(收录号:WOS:000333246400006)】；

基金：This research was financially supported by the National Natural Science Foundation of China (nos. 21276082 and 31200050) and the Ministry of Science and Technology, China (no. 2011CB710800).

语种：英文

外文关键词：DtManB; Fracturing fluids; Mannanase; Hydroxypropyl guar; Viscosity reduction

摘要：A new thermostable beta-1,4-mannanase (DtManB) cloned from Dictyoglomus thermophilum CGMCC 7283 showed the maximum activity towards hydroxypropyl guar gum at 80 degrees C, with a half-life of 46 h. DtManB exhibited good compatibility with various additives of fracturing fluid, retaining more than 50 % activity in all the cases tested. More importantly, premature degradation could be alleviated significantly when using DtManB as breaker, because at 27 and 50 degrees C it displayed merely 3.7 and 18.5 % activities compared to those at 80 degrees C. In a static test, 0.48 mg DtManB could break 200 mL borax cross-linked fracturing fluid dramatically at 80 degrees C, and merely 18 mPa s of the viscosity was detected even after the broken fluid was cooled down and only 161.4 mg L-1 of the residue was left after the enzymatic reaction. All these positive features demonstrate the great potential of this mannanase as a new enzyme breaker for application in enhanced recovery of petroleum oil.