Fine Interpretation Of The Structure Of Broken Small Fault Block And Control Of Oil And Gas By Fault

The study block is located in the southern part of the Sanzhao sag in the central depression of the Songliao Basin.The structural conditions of the block are complex and the faults in the area are broken.The fine structure interpretation and structural characteristics of 3D seismic data are analyzed in the study area,and the control effect of fault on oil and gas is analyzed,which is of great significance for oil and gas exploration and development in the study area.Based on the 3D seismic data and logging data of the study block,this paper uses the combination of well and seismic ideas to select 78 wells in the study area,and produces high-precision synthetic seismic records to perform fine-layer calibration of the target interval.The fine calibration of the seismic geological horizon determines the seismic reflection characteristics of the target horizon of the study area.After repeated stratigraphic comparison studies,combined with the seismic profile characteristics of the target interval,the detailed interpretation of the connected well profile is based on The layer performs fine layer interpretation and fault interpretation.It is first explained by the network density 32×32CDP,and then gradually encrypted to 1×1CDP.Because the fault of the study area is especially developed,the fault is small and complicated,which makes the fault characterization difficult.The horizontal slice technique,the slice of the coherent data along the layer,the azimuth attribute slice and other means determine the small fault and improve the structural interpretation accuracy.The three-dimensional velocity field suitable for this area is established by using the time-depth relationship,and finally a fine structure map with an interval of 5 m is obtained.Combining the structural interpretation plane results and the 3D seismic data profile analysis,the structural features of the target interval are analyzed.This time,a total of 494 faults were explained,and the data of fault tendency,general length,fault density,and fault distance were analyzed.It is concluded that the top structure of the Putaohua oil layer in the study area belongs to the southeastern high and low northwestern monoclinic structure.The top elevation of the grape flower is between-1180 and-1435 m,and the structural height difference is nearly 225 m.A total of 28 structural traps were developed on the top surface of the grape flower.The trap type was divided into two types: fault block trap and broken nose trap,mainly for fault block trap.The main fault of the top of the Putaohua oil layer is mainly in the northwest and northeast direction,the north-north and north-northwest faults,and a small number of northeast,northwest and near-east-west small faults are associated faults,and the faults are mutually sandwiched.Series broken block circle.The control of oil and gas by faults is mainly divided into: First,the vertical migration of oil and gas is mainly controlled by oil source faults.The oil source faults are active during the hydrocarbon expulsion period of the Qingshankou Formation source rocks,which provides conditions for the upward migration of oil and gas.It is a fault that has a certain control effect on the formation of traps,and provides conditions for the accumulation of oil and gas.