Characteristics of the Mesozoic reservoirs in the eastern depression of the Northern Yellow Sea Basin

The emphasis in the present paper is placed on eastern depression of the Northern Yellow Sea Basin as a Mesozoic-Cenozoic sedimentary basin.In the basin,the lithology contains fine-grained sandstone to siltstone intercalated with minor glutenite.The rock types include feldspar sandstone and feldspathic litharenite.The reservoir spaces are characterized by secondary solution openings and fissures,microporosity,fine throat to microthroat,indicating the low-porosity and low-permeability reservoirs.The fissures,sedimentary facies,and diagenesis are believed to be the main controls on the reservoir quality of the sandstones in the study area.The fissure zones and secondary porosity zones are suggested to be the favourable areas for future exploration.