Reservoir characteristics and genesis of slope fans in Dongying delta front

Slope fan refers to a sedimentary sand body which evolved from retransportation of delta or fan delta sand. It is caused by earthquakes and other factors and is transported in the form of slide, slump or debris flow. Based on core description, well logging and seismic data, combined with field investigation and sedimentation simulation, the reservoir characteristics and genesis were summarized. The lithology of a slope fan sand body is mainly fine sandstone and siltstone. Sedimentary structures are characterized by massive bedding, load cast and slump structures. It can be identified as a blocky or finger wireline log. The seismic facies is moundy or sphenoid shaped and the amplitude is moderate to strong. Slope fans are manifested as slide, slump and debris flow sand bodies. According to sedimentation simulation, 7 slope fan styles were differentiated. Combined with the geology of the Niuzhuang Subsag in the Dongying Sag, the distribution of slope fans was forecasted and two favorable prospecting target areas of slope fan were identified.