The development characteristics and main controlling factors of reservoirs in the Middle Permian Maokou Formation in Sichuan Basin were studied based on drilling and logging data

framework seismic sections and regional geolo-gical data.The relationship between paleostructure evolution and formation of geomorphology

karst landform and dolomitization zone of the Formation

was also discussed systematically to predict potential reservoir zones there.Study shows that the Caledonian Movement defined and shaped the fundamental landforms of the Middle & Lower Permian in the Basin and the Emei mantle plume's uprising exerted a continuous influence on the paleogeomorphology evolution in the whole Permian.As a result

southwestern Basin turned to an inherited paleogeomorphological high.It is not only a sedimentary paleogeomorphological high for the development of high energy bank depositsin the Formation but also a paleogeomorphological high for the development of weathering crust karst on top of the Formation.Emei tafrogeny provided migration pathways of hydrothermal fluid and acid diagenesis fluids for the overprint of multi-stage dolomitization and dissolution on early band deposits and karstification

thus largely controlled the distribution of dolomite reservoirs in the Formation.