Northern Songliao Basin Structural Interpretation And Reservoir Prediction In Ao158 Test Area

Ao 158 test area is located in the northern Songliao Basin,Zhaoyuan County,Daqing,with an area of 120 km2.The target reservoir is Fuyu reservoir,which is divided into F? and F? layers.The top-down geological development characteristics of FI,FII and their sublayers are meandering river,reticulated River and phreatic Delta deposits.The main composition of reservoir is channel sand.Sand bodies are characterized by many thin beds and large lateral variation.In order to upgrade the predicted reserves of Fuyu reservoir to the controlled reserves,fine structural interpretation and reservoir prediction in Ao158 test area were carried out to provide basis for deploying horizontal wells.There are two sets of seismic data in this area.The first set of seismic data is relatively poor in quality,low in resolution,unreasonable in interpretation of faults,and can not accurately divide favorable traps in reservoir prediction,so it can not meet the requirements of horizontal well deployment.Based on the evaluation and analysis of seismic data,the second set of seismic data is used to carry out structural interpretation and reservoir prediction in Ao158 experimental area.In structural interpretation,there is a lack of well location in the southern part of the test area,and pseudo-well technology is used to improve the well control range.In identifying small faults,coherence cube technique and curvature technique are used,and then the faults are synthetically depicted by combining seismic profiles.Due to the large lateral variation of sand body,the comprehensive analysis uses horizon control method,pseudo-well technology and variable speed mapping method to interpret the structure,and completes the structural map of each small sand body.From seismic data,the resolution of FI 1 layer under T2 strong reflection interface is extremely insufficient.To solve this problem,matching pursuit algorithm is used to remove strong reflection to improve the resolution of underlying strata.After treatment,the coaxiality of F?1 layer is clear on seismic section.The average amplitude attribute map of F 1 layer is used to predict sand body.It is found that the coincidence rate after removing strong reflection is greater than that before removing.Because conventional inversion can not achieve the recognition accuracy of thin interbedded sand bodies,different inversion methods are used to predict sand bodies.The natural gamma ray and resistivity reconstruction curve can better identify mudstone and sandstone.On this basis,geostatistics inversion technology and neural network inversion technology are used.Through two kinds of inversion,different inversion data are obtained.The structural overlap maps of wave impedance inversion and resistivity inversion of each formation are analyzed.The inversion profiles of connecting wells are compared.Combining with seismic data,the reliability of prediction is verified according to the drilling sandstone rate of wells,so as to determine the sand body distribution range of each formation.Provide reference for horizontal well deployment.