Fine Structural Interpretation And Reservoir Prediction In S Well Area Of Y Oilfield

The study area is located in the northeast slope zone of Sanzhao Sag in the north of Songliao Basin.The structure is a monocline from northeast to southwest,and the faults are well developed.The reservoir type is mainly delta distributary channel.The width of the channel is small in transverse direction,and the channel overlap is serious in different periods in vertical direction.Compound channel sand body appears in space,which makes it difficult to depict single sand body.In order to meet the needs of further development,it is necessary to make full use of current data for fine structural interpretation and reservoir prediction using seismic attributes.Based on well data and seismic data and under the guidance of sequence stratigraphy,this paper carries out stratigraphic correlation and establishes a high-precision sequence stratigraphic framework.The fine horizon interpretation and fault interpretation of six seismic reflection layers in the study area,T2,T2f2,T2f3,T2y1,T2y2 and T2y3,are accomplished by combining well-seismic calibration,using precisely calibrated synthetic records as the medium,and using coherence cube and time slice techniques as tools.The structural map is made by high-precision spatial velocity field,and the structural characteristics of the whole area are analyzed as follows: the east,high and West are tectonically constructed as a whole.Low and three faults can divide the study area into two uplifts,two depressions and two horst-grabens.Based on the high-precision sequence stratigraphic framework,the geological factors affecting the prediction ability of seismic attributed reservoirs are studied.The forward simulation method is used to analyze the three main factors affecting seismic response characteristics,namely,sandstone thickness,barrier thickness and channel width,and to optimize the main reservoirs.The method of reservoir classification is determined by reservoir characteristics analysis,reservoir structure anatomy,sand thickness statistics of each sedimentary unit and development characteristics of channel sandstone.According to the factors of channel width and sand body thickness,it can be divided into 13 primary sedimentary units and 11 secondary primary sedimentary units.For primary sedimentary units,the distribution characteristics of channel sand can be well predicted by means of root mean square amplitude,frequency division and 90 degree phase attributes;for secondary primary sedimentary units,the effect of single attribute slicing is poor,and the convergence and fusion method will be used to improve the channel prediction ability of primary sedimentary units.Finally,the study of well-seismic combined sedimentary microfacies of 24 main sedimentaryunits was completed,and its reliability was verified by well row,and the prediction of channel plane distribution characteristics in the study area was completed.