The Tectonic Styles of the Fault Depression Basin and Oil/Gas——The Example of the Eastern Sag of Liaohe Basin

There were different structures in different period on the fault depression basin. The structure style and sedimentary system responded, and collocated each other, therefore controlled the static geologic elements and the dynamic constitution of reservoirs formatting in the petroleum systems and decided the distribution of oil and gas. Structure styles in different period not only decided the hydrocarbon generating potential of all kinds of half-graben but also the distribution of sedimentary systems. The migration direction, style of oil and gas distribution and the advantageous structure and lithofacies belts were controlled by the effective correspondence of structure style and sedimentary systems. There were some disciplinarian in different half-graben of different period. Today's half-graben were overlapped by all kinds of half-graben of different period, in which oil and gas distribution were not equilibrium. The potential of the oil and gas were maximum in anticline reservoirs developing in roller half-graben, half-graben and ramp-sag, and next were structural-lithologic reservoirs, which was indicated by the reservoirs formation and evolution. The meaning that made it clear of the principles on distribution of oil and gas was significant especially to hidden reservoirs.