The Forming Mechanism and Identification Method of Shawodi Lithologic Traps in Junggar Basin

Lithologic trap is the most important type of traps in Shawodi area of Junggar basin. This paper presents the model of Shawodi litho-logic-trap reservoir. In light of the factors of petroleum accumulation, it is a reservoir probably accumulated together with palaeohigh and sedimentary sand bodies with characteristics of unobvious late reconstruction and primary accumulation. Synthetic seismogram is used for calibration of the stratigraphic units. Available lithologic reservoir models and such techniques as conventional seismic facies recognition, seismic attribute pickup and well log-constrained seismic inversion are applied for prediction of the sand bodies. The results show that in studied area the second member of Sangonghe formation is the potential reservoir, demonstrating the existence of the channel sand body in delta frontal facies; in western sag of Peng-1 Well develop several palaeohighs, which are the favorable areas for long-term hydrocarbon migration; in slope facies belt occur Jurassic delta sand bodies, which may help to shape litho-structural oil-gas reservoir; and the low-amplitude structure and lithologic trap in hinterland of Junggar basin should be as major targets for hydrocarbon prospecting.