Abstract:

Reservoirs in Shimen-Sangzhi from Sinian to Triassic mainly include two categories，namely，carbonate rocks and sandstone.On the basis of observation and detailed study on a large deal of common and casting rock thin section，the reservoir space in Shimen-Sangzhi from Sinian to Triassic is divided into primary remaining intergranular pore，secondary intergranular dissolution pore，secondary intragranular dissolution pore，pane pore，super large dissolved pore and cracks according to the structure and cause of the pores.Sedimentation and late diagenesis are found to be the main control factors of reservoir physical property in the area through analysis of the characteristics of reservoir physical property.And the influence of sedimentary facies on reservoir physical property is decisive.Accordingly，reservoir distribution is summarized.Generally speaking，in this set of formation，there are various types of reservoirs，but with poor reservoir physical properties，low porosity and low permeability reservoirs are dominant，except that the sandstone in the upper triassic Yingju formation is of good reservoir property.

Key words: reservoir space, northwestern Hunan, Sinian-Triassic, diagenesis, pore types