Near-surface geochemical exploration in the Changde inorganic gas reservoir, Songliao Basin

The Changde gas reservoir in the Songliao Basin is the only inorganic gas reservoir in the world which mainly produces alkane gas with a full geochemical complement. Therefore, the study of Changde inorganic gas reservoir has a great significance for the development of China's natural gas exploration. We designed a geochemical profile crossing wells Fangshen1 and Fangshen2 above the Changde gas reservoir, studied the near-surface display of different geochemical indicators, and selected effective geochemical methods and abnormal indicators. The analysis of methane carbon isotopes can help judge the inorganic origin of the reservoir.