The delta beach bar models of southwest slope in Qintong sag has been established according to the analy sis of sedimentary background, sedimentary characteristics, plane and vertical distribution. Engineered delta side margin beach bar is developed in the southwest slope, which is controlled by ancient landfotto, lake level, source supplied. When the lake level was high, the source supplied was not enough, and the transformation to the delta ffont was weak, the small scale beach bar was formed, which was discontinuous with the delta body. With dropping of the lake level, the source supplied was sufficient, the wave scour was strong, the beach bar was migrated inward, the beach bar which was continuous with the main body of the delta was formed. Lithologic oil reservoirs of deltaic fat sand bar are easy to form under the model that beach bar is discontinuous with the delta body; Upper dip and top out reservoirs of sandstone in beach bar are easy to form under the model that beach bar is continuous with the delta body. According to the sedimentary characteristics and models of the beach bar in the southwest slope, the paper point out the favorable exploration zone of the third member of Funing formation in the southwest slope.
the southwest slope
the third member of Funing formation
sedimentary char acteristics