The Characterization of Fan Delta Front Based on the Human–Machine Interactive Measurement and Flume Experiment

Fan delta, as an important sedimentary type at the margin of basin, is an important place for the enrichment of petroleum, natural gas and other geological resources. Limited by static data obtained from reservoirs and outcrops, the depositional architecture of fan delta front that based on sedimentary evolution remain poorly understood. Here, this paper obtains slope of substrate layer, hydrodynamic parameter and grain size from Sangyuan outcrop in Luanping Basin by the integration of field survey and unmanned aerial vehicle (UAV) observation. Then, flume experiments are presented, aiming to investigate the sedimentary evolution, architecture and formation mechanism of fan delta front. Three depositional processes of fan delta front are observed, including period of initial tongue-shaped deposit formation, period of sheet flow, cycles of alternating several small secondary channelized flows and fully confined channelized flow. The stacking patterns of architectural units vary from different depositional processes. Sedimentary background and supply conditions influence the depositional processes of fan delta front, and further control the mouth bar development. The results of flume experiments show that mouth bar development is negatively related to the slope of the substrate layer, discharge, sediment/water ratio, and grain size of sediment, but positively related to water depth.