A development model for Late Oligocene to Early Miocene reefs in the Liyue Basin of South China Sea

As a good reservoir for hydrocarbon accumulation, reefs have become a major concern of petroleum geologists for many years.The Liyue Basin in South China Sea is an excellent place for reef development. However, since lack of data, especially high quality seismic data, the research of Liyue Basin still remains in an initial stage up to date. This time, based on the re-processed 2D seismic data, using the up to date geological-geophysical analysis techniques, we studied the reef deposits during the period of T70-T50 in the Liyue Basin. It is found that reefs started growing in the time of T70-T60 and entered a booming stage in the period of T60-T50. Both hummocky shaped and lenticular reefs are discovered.The hummocky shaped reefs, which dominate the research area, can be further divided into single and multiple according to the number of hummocky structures. The growth of hummocky reefs is a combination of lateral retrogression and vertical accretion. From the view point of internal structure, the reef can be subdivided into 6 growth units, the first 3 stages shows a slow retrogression and the last 3 stages are the stages of rapid growth. The growth rate of the reefs is jointly controlled by sea level fluctuation, accommodation space and paleogeography.