Research On Sequence Characteristics Of TongBoMiao 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 analyses and studies the sequence stratigraphic framework and precipitation facies of the TongBoMiao formation in the northern area carefully and deeply. At the same time, combining with the research results of previous studies and the initial work above, the autho carries 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.In northern area, T3 and T4 which are the top and bottom interface of TongBoMiao group are a larger regional unconformity in the block sag. On the basis of analysing and drawing on the experience of the results of previous studies carefully,combining the well logging with seismic, we success on the unification of the drilling stratification and the seismic interface, and establish the sequence stratigraphic framework. we divide the TongBoMiao formation into one three-order sequence, four fouth-order sequences and we also study parasequence,parasequence set , systems tract and sedimentary system.Through ananlysing the controlling factors on the sequence such as structure subsidence, climatic change, sediment supply and lake level change in the research area, we interpret the effects of various controlling factors on the sequence development. The finding suggests that structure subsidence is the main factor on controlling the layer sequence development of the faulted period.Combining 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 are defined. The main precipitation facies in the TongBoMiao formation are braided fluvial delta facies , lacustrine facies, and volcanic facies.Finally, considering of the factor of oil generation, storage, cap rock, trap comprehensively, we point out the favorable exploration regions in the research area.