Reservoir-forming Conditions and Potential Analysis of Hu-Qing Fault Step Zone in Dongpu Depression

Hu - Qing fault step zone in Dongpu Depression has an echelon three - step structure. Fault nose and wall -corner fault block traps and structural and lithologic combination reservoirs exist in the first step zone in the depressed area; well- developed consequent fault nose and reverse roof fault block traps exist in the second step zone that is located between the two step faults and is the main area for hydrocarbon accumulation; while the third step zone is relatively simple where some reservoirs can form along well - developed local fault migration paths. The first step zone is close to oil sources, thus has large resource potentials and lithologic reservoirs are the main prospecting targets; the second step zone has been highly degree of prospecting, thus the focus of exploration should be put on looking for new oil - bearing layer series in the deep of main layers and shallow layers; and the third step zone is far away from oil sources, so exploration in this area should be carried out carefully.