Application from Combination of Slope Geometries and Shelf-Edge Trajectories to Find Large-Scale, Sand-Rich Deepwater Fan

Key words: 
• slope geometries /
• shelf-edge trajectories /
• combination method /
• deepwater fan

Abstract: In overseas selection stage, extremely low exploration degree and poor data of basin lead to work hard to carry out regular deepwater sedimentary analysis. Slope geometries and shelf-edge trajectories have abundant geological information. In this paper, on the basis of 2D seismic data, apply combination of slope geometries and shelf-edge trajectories to look for favorable distribution of large-scale, sand-rich deepwater fan. A basin develops three types of shelf-edge trajectories, including increasing shelf-edge trajectories, flat shelf-edge trajectories, decreasing shelf-edge trajectories. Progradational distance of linear-decreasing shelf-edge trajectories corresponding slope is longer, more beneficial to develop of large-scale deepwater fan deposits. At the same time, A basin develops four types of slope, including up convex slope, down concave slope, linear slope, and ramp-flat slope. Up convex slope and down concave slope have smaller slope angle and bigger slope width, more beneficial to sand mud differentiation and thus form deepwater fan deposits with better physical property of reservoir. Overlap favorable distribution of deepwater fan with large-scale and good physical property of reservoir during the same period. Overlapping area is the favorable distribution of large-scale, sand-rich deepwater fan, mainly located in the eastern corner and western area in the basin. Also, applying combination method of slope geometries and shelf-edge trajectories can establish sedimentary evolution model of basin during drifting period and analyze history of sedimentary evolution.