Abstract:

The formation and evolution of mud-mounts in the Yinggehai Basin are closely related to hydrocarbon generation,migration and accumulation.1.The mud mounts are distributed in Oligocene Yacheng Formation and the Miocene Sanya and Meishan Formations.The formation,evolution and distribution is decided by material base—the rapidly deposited,high thickness and undercompacting mud shales,regional dynamics and gravity factor.2.Mud mounts themselves are source rocks;abnormal high temperature and high pressure produced by their evolution is the motive force for hydrocarbon generation and migration,especially for high pressure natural gases soluted in water.3.The mud mount uplift structural belts are mostly distributed in the central part of the basin or the deeper parts of the depressions that are favourable locations for hydrocar-bon migration and accumulation.It is predicted that the pools of mud mounts within thebasin are mainly anticline,semianticline and noze types,and then faulted-noze type.4.The mud mount uplift structral belts in the central part and the fault-block structural belts in the southeast,having abundant hydrocarbon source and fine accumulation and preservation conditions,are favourable enrichment zones,and should be taken as im-portant targets for recent exploration;No.1 fault-structural belt could be taken as explo-ration target in the future due to its poor accumulation and preservation conditions.