The compound lithologic-structural oil reservoirs are located in Yaoyingtai regional uplift belt of Northeast China.Lithologically,there are mainly massive sandstones and fine-grained sandstones.The porosity and permeability of the reservoirs are generally quite low.The reservoirs consist of strata characterized by oil-water coexistence.The oil-water reservoirs of low porosity and permeability can hardly be discovered in geological exploration and borehole logging.Nevertheless,borehole geochemical exploration can reveal the features of oil-water coexistent strata.The authors combined the practice with research and application,and improved the recognition capacity steadily.As a result,a new borehole logging method has been established for recognizing oil-water coexistent reservoirs with low porosity and permeability.