ORIGIN AND SEDIMENTARY CHARACTERISTICS OF CANYON CHANNELS IN LEDONG AREA OF YINGGEHAI BASIN

Great attentions on canyon channel reservoirs have been raised in oil and gas exploration in recent years. The Member 2 of the Huangliu Formation in the Ledong area of the Yinggehai Basin is characterized by large canyon systems in NS direction. By use of the drilling, logging and seismic data and the approach of seismic sedimentology, we studied the origin of the canyon channels, sediment sources and sand body distribution patterns in this paper. The results suggests that the canyon system in the Ledong area is developed in the time of Member 2 of the Huangliu Formation, which is a period the low sea level mainly controlled by the regional regression event in the T40 period and the movement of the large strike-slip faults. Canyon fillings are mainly from the Hainan uplift. Small channels are observed in the surrounding areas. Influenced by the topography and hydrodynamic conditions, the canyon channel could be further divided into the erosional area, transportation and discharge area, and channel intersection area. The seismic features as well as sediments change greatly from areas to areas. Sandstones are mostly developed in the transportation and discharge and the channel intersection areas.