The Study Of High-resolution Sequence Stratigraphy And Favorable Target Prediction Of The Lower Part Of Member 1 Of Shahejie Formation Of Paleogene In MaDongDong Area

The deep zone of Member 1 of Shahejie Formation is above structural transform place, the intervals within hydrocarbon source system, so, there are favorable Belts which are developed lithologic hydrocarbon reservoir. With the guidance of the theory of High Resolution Sequence Stratigraphy, Sedimentology, Petroleum Geology, Structural Geology and Seismic Sedimentology, and based on 3D seismic reflection data, well loggings and cores, From Dongying Formation to Member 1 of Shahejie Formation in this area are underneath the same second-order sequences, and they could be further subdivided into seven third-order sequences, which are bonded by unconformities characterized by truncation or onlap contacts and its relevant conformity surfaces. The submember of the lower part of Member 1 of Shahejie Formation, as one of the main target intervals, is divided into three systems tracts, nine parasequence sets, and twenty parasequence.The temporal and spatial evolution is revealed through the established chronostratigraphic framework with the research of sedimentary microfacies and the distribution of sandbody. The main target intervals characterize gravity flow deposit in deep water, and source area of the gravity flow channel of oil formations is steady, which coming from north-east of the area, and the channel change little as a whole. Gravity-flow channel sandbodies distribute zonally; Gravity-flow channel deposit perpendicular to the source area appears as lenticular, and the continuity paralleling to source area is better. Gravity-flow deposit of the target intervals could be further subdivided into four micro faces of the water channel, overbank, inner-channel and lake basin.The research indicates that the sandbodies of transgressive system tracts are undeveloped, the sandbodies of LST and HST are developed. However, the sandbodies of LST are better developed than that of HST, and the laterally continuity is also better. 3D Seismic Data S/N ratio of this study area is better, but the resolution is low, so, it is just settling for structural implementation and the reservoir prediction of the oil-sand formations.The post-stacked seismic data fedility frequency -broadening processing techonlogy could enhance the resolution of seismic data. The corresponding relations between lithologic character and wave impedance of the target zone is complicated, so, it is difficult for the conventional wave impedance inversion technique to identify sandstone and mudstone, and GR curve reconstruction technique could identify sandstone and mudstone correctly.The study shows that the reservoirs are controlled by structure, sequence, sedimentation and diagenesis.This area has good prospects for oil and gas exploration and evaluation.