ANALYSIS OF THE FEATURES OF SEQUENCE STRATIGRAPHY AND SPATIAL DISTRIBUTION OF SANDSTONEs IN THE BAODAO AREA, QIONGDONGNAN BASIN

Based on the principle of sequence stratigraphy, according to the analysis of seismic and well-log sequence stratigraphy, fourteen seismic depositional sequences are identified in the Tertiary of the Baodao area, Qiongdongnan basin, and the characteristics of various sequences are analyzed. In addition, the paper summarizes sandstone types in different systems tracts and analyzes in detail the spatial distribution of sandstones in different systems tracts. The study shows that the advantageous sandstones in the area have the following distribution characteristics:in the environment of growth faults, sandstones are mainly distributed in the downthrown block of a boundary fault; in a lowstand systems tract, sandstones are mainly distributed in lowstand wedges, slope fans, basin-floor fans, fan deltas, deltas and submarine canyons; in a transgressive systems tract, sandstones are mainly distributed in sandbars and sand-beaches; and in a highstand systems tract, sandstones are mainly distributed in deltas, fan deltas and submarine fans.