Influenced by the underwater paleouplift and multi-stage structural extrusion of Leshan-Longnyusi

Yuxi Block gradually deepens from north to south

and has the characteristics of large thickness change of type I reservoir and low porosity（less than 4.5 %）

it is very important to study the pore structure of high quality shale. Traditional shale pore analysis technology has weak identification ability for different types and sizes of micro nano pores. Through an optimized analysis method based on maps image

it can reduce the space-time complexity of the algorithm and improve the applicability on the premise of effectively identifying and statistics the organic and inorganic pore fractures of shale. Characterization of organic pore fractures in Longmaxi formation is about 300 μm

inorganic pore seam with a visual field of view length of 500 μm. The diameter or opening range of organic pore gap detected by maps image is mostly between 0~100 nm. The organic matter content and organic matter porosity are different

and the abundance of organic matter is not the only control factor for the development of organic matter pores.