Five types of sand-conglomerate fanbodies

including alluvial fan

fandelta

coastal submerged fan

steep-slope deep water turbidite fan and slump turbidite fan

are developed on the northern steep-slope belt of Dongying depression. From the marginal salient to the basin's hydrocarbon-generating center

the oil reservoirs in these sand-conglomerate fanbodies are successively the stratigraphic-lithologic reservoirs

structural-lithologic reservoirs and lithologic reservoirs.In the steep-slope belt

the 4th member and 3rd member of Shahejie Formation are excellent source rocks

with a maximum thickness of 4000m

where the type I-Ⅱ kerogen are present.The organic-carbon content for both source rocks ranges from 0.5 to 3.5 percent.Oil and gas were moved into the fanbodies

developed on the middle-upper parts of steep-slope belt

through the composite conduit system consisting of faults

sand layers and sequence boundaries

which is characterized by stepped migration in vertical and lateral transformation.The oil reservoirs in the fanbodies experienced the hydrocarbon-charging stages corresponding to the deposition periods of Dongying

Guantao and Minghuazhen Formations.The reservoiring process

however

occurred mainly during the deposition of Guantao and Minghuazhen Formations.The dynamic process of oil and gas accumulation can be summarized as the reservoiring model of the fault terrace type of the sand-conglomerate fanbodies in steep-slope belt.