Research On Sequence Characteristics Of Denglouku Formation In Southeastern Uplifted Area, Songliao Basin

Based on the latest' theories and methods such as the sequence stratigraphy, sedimentology, seismic stratigraphy, reservoir 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 Denglouku formation in the southeastern uplift area carefully and deeply.At the same time,combined with the tectonic geological features of the southeastern uplift area,the author studied the combination regularity of oil generation, storage, cap rock of the Denglouku formation and predicted the distribution range of the favorable sand body.The results enrich the theories of the sequence stratigraphy and the sedimentology and have actual guiding significances on the future hydrocarbon exploration and development as well as the allocation of the well location in the area.On the basis of analysing and drawing on the experience of the results of previous studies carefully,combined the well logging with seismic, the unification of the drilling stratification and the seismic interface are achieved,the sequence stratigraphic framework are established. From top to bottom, the Denglouku formation can be divided into two third-order sequences,they are II 1-d1 and II 1-d2. All system tracts are fully developed in each third-order sequence.The interface of the two third-order sequence is located at the conversion surface of the lithology and electric nature.Below the interface it presents the character of partly truncation,and above the interface it presents the character of onlap.Through ananlysing the control factor of sequence such as tectonic subsidence, climate change, sediment supply and lake level changes in the research area,the effects of various control factor on the sequence development are interpreted.It is suggested that tectonic subsidence is the main factor of controlling the layer sequence development of the faulted period,the climate change is the main factor of controlling the layer sequence development of the depression period.Combine with the data of crop, seismic, well drilling and well logging,the characters of precipitation facies, depositional model and depositional systems distribution of the Denglouku formation are defined.Fan-delta facies,braided fluvial facies,braided fluvial delta facies and coastal shallow lake intrafacies are the main precipitation facies in the Denglouku formation.Finally,considered the factor of oil generation, storage, cap rock,trap comprehensively,the favorable exploration regions can be pointed out in the research area.