Abstract: Sublacustrine fan is a kind of deposit of gravity flow developed on slope of deep lake-bathyal subfacies area, which occurs widely in most of the continental sedimentary basins. In view of its distribution in group, it has become a major domain for petroleum exploration of lithologic reservoirs. Taking the sublacustrine fan of Lower Wuerhe formation of Permian in K-81 Well east area of Karamay oilfield as an example, this paper presents the seismic identification model for the sublacustrine in deep lake-bathyal subfacies area from the outside reflection feature and inner reflected structure of the seismic reflection event, integrated with seismic multi-attribute analysis, spectrum decomposition and layer flattening techniques for verification, and finally confirms its range in plane distribution.

Key words: 3D seismic survey, sublacustrine fan, lithologic trap, seismic attribute, spectrum decomposition, layer flattening