YakaiGasfield is a typical compound sandstone gas reservoir controlled by structure-lithology, and characterized by lowporosity and lowpermeability, gas/water inversion and abnormal formation pressure. Comprehensive study shows that the gas/water relation is influenced not only by structure, but also by sand body piching and physical property changing, so it is a relatively complex particular gas reservoir. There exist two types of abnormal gas/water relation in this gas reservoir, and the forming reason and distribution areas of these two types of gas/water relation are analyzed. It is considered that there developed favorable stratigraphic-lithologic traps in the northwestern area of the gas reservoir. Two wells deployed in the northwestern area have obtained commercial oil and gas flow, and the further rolling exploration
extension direction is pointed out.