Controlling of Fault Condensed Belts to Oil Migration and Accumulation of Sourcerock below Reservoir in Depression——an example from P oil layer of Sanzhao depression in Songliao Basion

In order to study the controlling of fault condensed belts in accumulation and distribution of oil in Putaohua oil layer in Sanzhao depression,development and constitution of fault condensed belts is researched by use of seismic interpretation.It is considered that there are a large number of T11 faults in Putaohua oil layer of Sanzhao depression.The faults can be divided into 4 types: faults forming in faulted period and faulting in depression period,faults forming in faulted period and faulting in depression period and inversion period,faults forming in depression period and fault forming in depression period and faulting in inversion period.There are 29 fault condensed belts in the plane.They distributed mainly in the north and centre of Sanzhao depression and in NNW,near SN and NNE direction.By studying the relation between fault condensed belts and Putaohua oil layer,it is concluded that fault condensed belts is closely related to oil migration and accumulation and its controlling effects in oil accumulation and distribution are in 3 aspects: ① The boundary faults of fault condensed belts are oil migration pathways,and oil distributed near the fault condensed belts in a large area;② Oil more enriched in intersection of fault condensed belts;③ Cross fault structure in fault condensed belts is favorable for oil accumulation.