Hydrocarbon Accumulation Model At The Shengtuo Area And Petroleum Prospects In The Dongying Depression

Based on the modern theory of oil and gas accumulation, a comprehensive study is performed on the Shengtuo area with geological, geophysical and geochemical data in the area. An accumulation model and a distribution regularity of hydrocarbon is postulated and new objects of exploration and development are pointed out for the area. All these conclusions are instructive to the forecasting of subtle trap pools.A detailed correlation of oil and source rocks is completed, and real effective source rocks are defined. The geological and geochemical characters of source rocks of Shahejie Formation(Es) in adjacent the Lijin Sag and the Minfeng Sag are recognized, and the distribution of effective source rock are made clear. The author believes that the effective source rock plays a controlling role on the formation of composite hydrocarbon accumulation in the Shengtuo area.Based on analysis of fault morphology, and tectonic dynamics, the author finds thatShengbei Fault controlled the deposit system, reservoir distribution and various types oftraps in th earea. At the same time structure stress field was analyzed, and the fluid flow direction of hydrocarbon migration and accumulation were represented.This disertation established the stratigraphy sequence and deposition system of the Es reservoir. In addition, a high resolution of stratigraphic sequence frame of main reservoirs in Esa Member is represented, and evaluation on the reservoirs is also made.The path and time of hydrocarbon migration are studied based on the study of effective source rocks, fault structure and reservoir deposit system, which shows that Shengbei Fault and other minor faults are the main paths between source rock sand reservoir in traps, and the fan-delta sandstones and sub-water fan sandstones are another kind of migration path. Therefore most sandstone bodies connected with the faults are infilled with hydrocarbon and with high oil saturation.Simulation experiments of oil pool formation in a single sandstone block with physical simulation equipment for the first time, in order recovery of the oil accumulation oringin. The experiments show that porosity and permeability of sandstones strongly control on oil infilling into the sandstones.Although about 4 × 108t oil reserves have been found in the Shengtuo area for 40 years exploration, the author believe that a large resource potential still exists in this area. Some sandstone bodies have excellent probility of hydrocarbon accumulation, such as delta-fan sandstone bodies, nearshore sub-water delta sandstone bodies and turbidity-fan sandstones of lower part of the Es3 and Es4 Member in the Shengtuo area.