Characteristics and significance of natural gas hydrate reservoir of Triassic in well QH-2 in Harlahu Depression of Southern Qilian Basin
XIAO Rui1, ZHU youhai1, LU Zhenquan1, LIU Hui1, PANG Shouji1, ZHANG Shuai1, FAN Dongwen1,2, WANG Weichao3
1. Oil and Gas Survey, China Geological Survey, Beijing 100083, China;
2. China University of Geosciences (Beijing),Beijing 100083, China;
3. Qinghai No.105 Coal Geological Exploration Team, Xining 810007, China
Abstract：Harlahu Depression is basically a geological blank area now. Few studies on the formation and distribution of natural gas hydrate have been published, especially the research and understanding of natural gas hydrate reservoir in this area. The borehole QH-2 is located in the western part of Harlahu Depression of South Qilian Basin, and it was the first deep drilling hole for natural gas hydrate investigation in this area, in which Quaternary,Neogene—Paleogene and Triassic strata were drilled. The authors took the core of Triassic reservoir in well QH-2 as the research object to study the reservoir characteristics of Harlahu Depression, through the thin section observation of rock, porosity, permeability, rock density, casting thin section and other physical property tests, as well as the logging data. The research shows that Triassic reservoir of well QH-2 is widely distributed with great thickness. However, the physical property of the reservoir is poor, and most parts of the reservoir were unconventional reservoirs. The fractures are not developed, so it is difficult to form fracture type hydrate and pore type hydrate in the consolidated rock stratum similar to Muli area. While, the thick Quaternary loose sediments and Tertiary strata with relatively developed fissures were developed under the permafrost regions in this area, which may provide a better reservoir space for the formation of natural gas hydrate.
肖睿, 祝有海, 卢振权, 刘晖, 庞守吉, 张帅, 范东稳, 王伟超. 南祁连盆地哈拉湖坳陷青徳地2井三叠系天然气水合物储层特征及其意义[J]. 中国地质调查, 2020, 7(4): 20-27.
XIAO Rui, ZHU youhai, LU Zhenquan, LIU Hui, PANG Shouji, ZHANG Shuai, FAN Dongwen, WANG Weichao. Characteristics and significance of natural gas hydrate reservoir of Triassic in well QH-2 in Harlahu Depression of Southern Qilian Basin. , 2020, 7(4): 20-27.
2020, Vol. 7 
