摘要
The Nanpu sag is one of the most petroliferous sags in Bohaiwan basin,within which the hydrocarbons are unevenly distributed.Horizontally,oil resources are mainly distributed in the Nanpu No.1 tectonic zone,followed by the No.2 tectonic zone,while gas resources are mainly distributed in the Nanpu No.1,No.2 and No.5 tectonic zone.In terms of land and offshore,oil and gas resources are mainly distributed in beach areas.Vertically,oil and gas resources are mainly distributed in above-source plays,and oil and gas resources in Member 1 of the Dongying Formation are the most,and relatively fewer in inside-source plays and belowsource plays.According to comprehensive analysis on elements of hydrocarbon accumulation,oil and gas distribution in the Nanpu sag are mainly controlled by the following factors.Firstly,source rocks have controlled the distribution areas of hydrocarbon reservoirs.The study shows more than 80% of hydrocarbon reservoirs have located in the place which is within 15 kilometers from expulsion center.Secondly,the favorable sedimentary facies have controlled the sand distribution and reservoir properties,thus they have controlled the distribution of the lays of hydrocarbon reservoirs and their scales.Finally,faults are the most important factor controlling the hydrocarbon reservoirs’ distribution.On the one hand,faults have controlled the trap types and their spatial distribution,further,the size and location of hydrocarbon reservoirs.On the other hand,as channels for hydrocarbon’s vertical migration,faults control their vertical migration distance.To sum up,the hydrocarbon distribution of the Nanpu sag is under the controlling effects of the combination of source rocks,sedimentary facies and faults.The deltas near the source rocks,channel sands and the fault zones interconnecting vertically are favorable exploration areas.
