Study On Seismic Reflection Characteristic Analysis And Identification Method Of Fault-karst Carbonate Reservoir In Shunbei Area

Carbonate reservoirs play an increasingly important role with the development of oil and gas exploration in many countries,among which the fractured reservoir is the main form of carbonate reservoir formation.In fractured reservoirs,faults and karst caves form the basis of oil and gas reservoirs.Faults are channels for oil and gas migration,while karst caves are places for oil and gas storage.Fault identification is the key factor to identify carbonate reservoir.Based on the study of reservoir characteristics of fault,karstification and fault-controlled karst,the concept of fault-karst carbonate reservoir was first established in Shunbei area.During the migration of underground water in the fractures,large karst caves will be eroded on both sides of the fractures.After oil and gas are injected into these caves,special fault-karst carbonate reservoir will be formed.The 3d seismic volume data is large,the environment of data collection is changeable,and the noise composition is complex.However,the fault,pinch-out area and other abnormal geological bodies in carbonate seismic data are often important indicators of oil and gas reservoirs,so it is very important to retain these abnormal characteristics while improving the signal-to-noise ratio.On the basis of smoothing the continuous layer,the structure-oriented filtering technology enhances the fault and pinch-out point,improves the signal-to-noise ratio of seismic signals and effectively highlights the fault information.Wavelet transform has good time-frequency localization and spectral whitening is an effective frequency compensation method in high resolution processing.By combining the two methods,we can generate a high resolution seismic data processing method.Seismic attribution refers to some effective seismic information extracted from seismic data,through which we can observe the properties that cannot be directly displayed in the original seismic data.There are many kinds of seismic attributions,and different seismic attributions can reflect different structural characteristic information.By studying the principle of seismic attributions and analyzing the seismic data,the appropriate seismic attributions are selected.Besides,we generate a set of attribution identification method for fault-karst carbonate reservoirs,which can provide guidance and help for the processing of similar reservoirs in the future.