Open AccessAnalysis on Geological Conditions of Chang 7 Shale Gas Accumulation in Longdong Area in Ordos Basin
Author(s) -
Zhenhua Li,
Ke Gai,
Lan Yu,
Suya Zhang,
Ning Sun,
Xiangyang Li
Publication year - 2019
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/300/2/022093
Subject(s) - oil shale , geology , sedimentology , pyrite , organic geochemistry , quartz , geochemistry , organic matter , feldspar , carbonate , total organic carbon , mineralogy , structural basin , source rock , geomorphology , paleontology , environmental chemistry , chemistry , organic chemistry
The geological conditions of Chang 7 shale gas accumulation in Longdong area are analyzed from sedimentology, petrology and organic geochemical characteristics in this paper. The study shows that Chang 7 shale in Longdong area is mainly deposited in deep lake and semi deep lake, with thickness ranging from 10 m to 40 m. The shale is mainly composed of quartz, feldspar, clay minerals and a small amount of carbonate and pyrite, and its brittleness is high. TOC ranges from 1.5% to 20.0%, with an average of 7.9%, and hydrocarbon generation potential (S1+S2) ranges from 0.67 mg/g to 33.53 mg/g, with an average of 15.81 mg/g. The main organic matter belongs to type I and II, Ro ranges from 0.7% to 1.2%. It can be concluded that Chang 7 shale in Longdong area possesses favourable conditions for shale gas accumulation.