Diagenesis and porosity evolution of carbonate rocks of the Middle Triassic Leikoupo Formation in the south-central part of Sichuan Basin,China

The Leikoupo Formation of Middle Triassic is the main gas-producing layer in the central Sichuan Basin.This paper primarily studies the diagenesis type and succession,pore type and porosity evolution about the formation by analysing the thin sections.Both sedimentary environment and diagenetic environment have influence on the physical property of the rocks in the formation.The constructive diagenesis is dissolution and mixing-water dolomitization.The main pore types are intercrystal pore and solution pore.