Application of seismic interference in the stratigraphic pinch-out boundary prediction, an example from southern Liaodong Bay, Bohai Offshore, China

Summary With the acceleration of oil and gas exploration in Bohai Offshore, sandstone reservoir with stratigraphic trap has been the important target for future reservoir growth in southern Liaodong Bay. In order to accurately estimate resources in stratigraphic trap and mitigate relating risk of offshore exploration, it is critical to identify stratigraphic pinch-out boundaries’ location precisely. It is usually challenging using conventional manual seismic interpretation method because of seismic tuning effect of pinch-out boundary. The main objective of this study is to improve identification accuracy of pinch-out boundaries. In this study, wave-equation forward models, well logs and three-dimensional seismic data are integrated to investigate geophysical responses and identify sensitive seismic attributes relating to stratigraphic pinch-out boundaries. This study indicates the actual stratigraphic pinch-out boundaries of sandstone reservoir are generally located in the up-dip direction of the vanishing point of seismic events. By detailed analyzing the subtle variation of closely spaced reflections, an innovative workflow is proposed to predict pinch-out boundaries more accurately and clearly.