STRUCTURAL PATTERNS AND HYDROCARBON DISTRIBUTION IN LIUPANSHAN BASIN

The Liupanshan Basin is a composite-superimposed basin developed in the early Paleozoic as a rift system at the trident juncture of the Qinling, Qilian and Helan Mountains. Multi-phases of tectonic movements, namely, Indo-China, Yanshan and Himalayan tectonic movements, multi-phase reconstruction and later adjustment, especially the Mesozoic and Cenozoic extensional strike-slip, thrust, overthrust, and structural reverse resulted in a variety of structural patterns in the Mesozoic and Cenozoic tectonic layers in the Liupanshan Basin. Through comprehensive analysis of drilling and seismic data, three major structural patterns were recognized, namely, compressive, extensional and inverted structure patterns, of which the compressive is the most important one, and the inverted structure is the result of the regional tectonic background. Upon the different structural patterns, there are different types of traps. It is proposed that future hydrocarbon exploration should focus more on regional deep structure along the piedmont zone as well as the low salient part of the depression zone in the Liupanshan Basin.