Identification of Transfer Structure at Southern Steep Slope Belt and Its Control on the Petroleum Accumulation, S Depression in M Basin

Based on the analysis of the growth process of the southern boundary fault (FS), the location, type and characteristics of transfer zone developed at the Su south steep slope zone was studied. The control of this transfer zone on the sandbodies deposition at the steep slope zone during the Abu Garba syn-rifting period and the prediction of favorable area for forming lithological reservoirs as well as their accumulation model were also analyzed. Result shows that Southern boundary fault was composed by two segment faults and a synthetic transfer zone between two adjoining segment faults developed along this fault. This zone has an obvious impact on the the sandbodies depositing at the steep slope belt during Abu Gabra syn-rifting period, Sand ratio has an abnormally higher value in the position close to the transfer zone than that developed far away from transfer zone. The mode of transfer zone controlling the sandbodies deposition could be divided into two types. There is a potential favourable area for exploring the lithogical reservoirs at the steep slope belt, which is close to the hydrocarbon generation and expulsion center, located in the updip direction of the transverse anticlines and on the paths of oil and gas secondary migration.