Abstract:The paper gives a result of study integrating the characteristics of seismic reflection waves of 346 seismic profiles in Sichuan, with log data of the gas-water distribution of two carbonate reflectors at the Middle-Lower Triassic(T1-2)erosional surface and the top of the Permian Yangxin Series (P1) in the area. After a study of 172 wells in T1-2 and 109 wells in P1 in the light of the principle of the spacing between the wells and seismic profiles<500 m, it is found that not only the pore-fracture ratio of the sum of wells that show suspicious and non-seismic reflection is 1.3 to 1.6 times that of reliable seismic reflection wells but the high-and intermediate-producing wells among the former are more than those among the latter. Among other things the high-and intermediate-producing wells in the JialingJiang Formation (T1/j) are even 4.7 times higher. It is considered that this is probably the manifestation of the degree of pore-fracture development of the hinterland rocks on the seismic reflection records, thus providing important grounds for predicting the pore-fracture development in the hinterland reservoirs in the area. The suspicious and nonseismic reflection zones in the area are not only widely found in positive structure, but also present often in negative structure. Exploration work shows that gas and water are not distributed according to the model anticlinal traps. There is water in the high part of the anticlinal gas trap and gas outside the trap. This is the manifestation of a fractured gas field with heterogeneous pore-fractures and poor interconnection. Therefore, if gas source is abundant and there exists no deep and large tension fractures, gas may be possibly accumulated in these zones, even in the axial region of a syncline. It follows that the exploration prospect may be expanded greatly and that gas reserves may increase.