Study On High Resolution Sequence Stratigraphy And Reservoir Heterogeneity In Shallow Water Delta

Based on the theory of high resolution sequence stratigraphy,using abundant cores,logging and 3D seismic data,The Fuyu oil reservoir in block 101 of Daqing oil field is divided into the following 2 long term base level cycles,the 6 middle of the medium-term base level cycles,and the 35 short-term base level cycles,The method of the comparison of the approximate base level cycle interface under the control of step by step standard time surface is studied,The high resolution sequence stratigraphic framework of Fuyu oil reservoir is established.Under the control of isochronous stratigraphic framework,the data of core,logging and development are used,The distribution characteristics of sedimentary microfacies in short-term base level cycles are systematically studied,we build the depositional system of shallow water delta in Fuyu oil reservoir is developed from the early and middle stage of slow water to the middle and late stage.Based on the study of high resolution sequence stratigraphic framework and sedimentary microfacies,the systematic study on the heterogeneity of the short-term base level cycles was carried out.By the analysis of the inner layer,inter layer and plane heterogeneity of the reservoir of the short-term base level cycle in Fuyu reservoir,The results show that the heterogeneity is mainly medium and strong heterogeneity,and a few of them are weak heterogeneity.Under the framework of high resolution sequence stratigraphy,The change of the sedimentary environment caused by the base level cycle and the accompanying spatial variation can play an important role in controlling the heterogeneity of the reservoir,With the rise of the long term datum level,the internal and the plane heterogeneity of the short-term base level cycles become stronger,With the decline of long-term datum,the opposite;Inter layer heterogeneity controlled by the medium-term base level cycle,The transition surface of the base level rotation is the rising base level cycle,Inter layer heterogeneity is weak,On the basis of the increase of the rotation of the datum plane to the decline of the base level cycle,Inter layer heterogeneity is strong;At the interface between the two successive mid-down datum plane cycle,If the former is a low available space for the decline of the base level cycle,Inter layer heterogeneity is weak.