Abstract: Quaternary biogenic gas reservoir located in Sanhu area in Qaidam Basin features in low altitude structures, low compaction effect, high porosity, shallow burial depth and big thickness. For these reasons, gas reservoir has particular surface topography, geophysical and geochemical exploration abnormalities. On this basis, this paper explained and predicted shallow gas with remote sensing, geophysical and geochemical exploration methods. Through contrastive analysis of such gas fields as Tainan and Sebei No.1, this paper put forward the distributive characteristics that Sanhu gas reservoir agreed with negative gravity anomaly to a high degree, and the anomaly of high methane values of low-amplitude structure and chemical exploration, and predicted three zones favorable for exploration such as the W zone of Taijinar-Tuofengshan-northern Yanhu, the nearly E-W zone of Tainan-Sebei No.1-Sebei No.2, and the S-N zone of eastern Dabuxun Lake, two comparatively favorable zones such as northern Senie Lake and Dabuxun Lake as well as the western part, and three favorable targets such as eastern Sebei No.2 gas field, western Yanhu gas field and eastern Tainan gas field.

Key words: Qaidam Basin, Sanhu area, Quaternary biogas, remote sensing, gravity, aeromagnetic, chemical exploration, comprehensive analysis and prediction