Title
"Source-Transportation-Sink" analysis method and application in continental lacustrine basin sedimentary system based on 2D seismic data: an example from Wenchang Formation of long axis direction, Kaiping Sag, Pearl River Mouth Basin
Abstract
For some continental lacustrine basins with low degree of exploration and complex structure, it is very difficult to recognize from source to sink systematically with traditional seismic facies analysis. This paper attempts to use the thought of"Source-Transportation-Sink" in the research of depositional system in continental lacustrine basins. Using palaeogeomorphology, paleocurrent, sequence stratigraphy, and seismic facies analysis, sediment sources, transport pathway and depositional pattern are analyzed. A set of analysis methods is established, which involves three steps: from macroscopic to mid-gradational, and finally to microcosmic. Based on the 2D seismic data, this paper summarizes the sedimentary facies evolution of Wenchang Formation in the direction of the long axis of Kaiping Sag: in the early stage, Kaiping Sag was separated into 5 secondary sags, which mainly developed fan delta near source; in the middle stage, water in the 5 secondary sags connected together, the main sag became the sedimentary center, which developed deep and semi-deep lacustrine sediments; in the late stage, shallow braided river delta, which originated from the west of Kaiping Sag, was widely distributed in the main sag. According to the analysis results, the reservoir and caprock conditions of Wenchang Formation in Kai 2 structural belt are good, which has the potential of oil and gas exploration.
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