Identification and characteristics of ancient mud-rich low-sinuosity rivers

Aim Ancient mud-rich low-sinuosity rivers are summarized and separated from meandering river so as to understand exactly the relative depositional characteristics and channel sandstone distribution.Insight into the mud-rich low-sinuosity rivers can help for reservoir characterization and prediction.Methods The distributing and extension of ancient low-sinuosity channel can be identified from 3-D seismic data.They are neither braided river nor meandering rivers.The characteristics of channel belts are compared with overbanks,and compared with deposition of other types of rivers in different basin and different geologic times.Results The common depositional characteristics of ancient mud-rich low-sinuosity river are realized:Ancient mud-rich low-sinuosity rivers are invariably developed in lower fan and frontier fan environment of dry climate.They are planar either mono-channel system or multi-channel system that braches or cross each other.A mono-channel sandbody is usually several-meter thick and small in scale and width-thickness ration.Conclusion Ancient mud-rich low-sinuosity channels identified from 3-D seismic data are possibly a river belt in which multi-phase channel sands likely deposited.