A Study For Seismic Interpretation Techniques For Stratigraphic Reservoir Detection In Dainan Formation In West Qintong Depress

Qintong depress of North Jiangsu basin is a high degree exploration basin,in the past,the exploration was focused on the structural trap.With the exploration degree is more and more high,the difficulty of identifying new structural trap increases;lithologic trap exploration has become a hot spot.As the stratigraphic reservoir identifying job just starting in Qintong depress,in order to better promote this job,a set of techniques applicable to the seismic interpretation of North Jiangsu basin needs to be developed.This paper sums up such a set of techniques through several years seismic interpretation experience in hydrocarbon exploration.Seismic resolution can be improved to enhance the seismic data quality,by the application of specific frequency signal identification,data frequency extension,spectrum balance technology in the seismic process.Seismic coherence technology,instantaneous phase and spectrum decomposition technology can help identify the stratum eroding line,in the definition of stratigraphic reservoir's detail.Error exits between the pitching-out point identified in seismic event and the actual stratigraphic point.By setting the angle extrapolation model,the actual stratigraphic pitching-out point can be more accurately located.Normalization of well logging data in data QC process and quasi-acoustic constructing technique enhance the accuracy of seismic inversion.Simultaneously,stochastic seismic inversion based on geology statistics helps to improve the accuracy of sandbody prediction,in the explorated basin which has abundant well data.Through analysis,the seismiccharacteristics that sensitive to stratigraphic reservoir of Dainan formation are spotted,bright spot technique and frequency attenuation attribute are found useful in the hydrocarbon detection.The application of all those techniques mentioned above,achieved good results in the stratigraphic reservoir detection in Dainan formation in Qintong depress in the Jiangsu basin.In the west slope of Qintong Chen Jiashe,Shuaibei and Baima area in the Dainan,Formation overlying pinchout belt type reservoir breakthrough,implements the new oil-bearing area 2.16km~2,implements quality commercial reserves 235×10~4t,newly adds capacity 3.9×10~4t totally.