Research On Sequence Characteristics Of Tong Bomiao Group In Southern Area Of Wuerxun Hollow

Based on the latest theories and methods of the sequence stratigraphy, sedimentology, structural geology, petroleum geology, as well as the analytical data of seismic, well logging,core,the author analysed and studied the sequence stratigraphic framework and precipitation facies of the TongBoMiao formation in the southern area carefully and deeply.At the same time,combined with the research results of previous studies and the initial work above,the autho carried on the forecast about the advantageous area.The results enrich the theories of the sequence stratigraphy and the sedimentology ,and they also have actual guiding significances on the future hydrocarbon exploration and development as well as the allocation of the well location in the area.T3 which is the interface between TongBoMiao and NanTun group is a larger regional unconformity,TaMuLanGou group in wunan is missing entirety. T4 was on the superd by T5,that is the end of the TongBoMiao group is T5.On the basis of analysing and drawing on the experience of the results of previous studies carefully,combined the well logging with seismic, we successed on the unification of the drilling stratification and the seismic interface,and established the sequence stratigraphic framework.At last ,we divided the TongBoMiao formation into four fouth-order sequences from bottom to top, as TSQ1,TSQ2,TSQ3 and TSQ4.All system tracts are fully developed in each four-order sequence.We studied the deposition system of each sequence basised on the division in the four sequences.Through ananlysing the controlling factors on the sequence such as structure subsidence, climatic change, sediment supplie and lake level changes in the research area,we interpreted the effects of various controlling factors on the sequence development.The finding suggested that structure subsidence was the main factor on controlling the layer sequence development of the faulted period.Combined with the data of crop, seismic, well drilling and logging,the characters of precipitation facies,depositional model and depositional systems distribution of the TongBoMiao formation were defined. The main precipitation facies in the NanTun formation were Fan-delta facies,,lacustrine facies, and volcanic facies.Finally,based on the work accomplished by this project and results of previous studies,we pointed out the favorable exploration regions in the research.