According to the description of cores

conventional thin sections

injecting thin sections

SEM observation

X-ray analysis of clay minerials and pattern analysis of pore structure

it is found that the heterogeneity and physical property of the sandy river bed

sandbar deposit

conglomeratic river bed

flood plain deposit and debris flow deposit gradully increase and vary worse and wores.Based on the relationship between pore throat types and rock fabric

six types of reservoir pore structure models could be established.The pore structure models of type-Ⅰ and type-Ⅱ reservoirs are mainly primary intergranular pore and solution pore types;that of type-Ⅲ are solution pore micropore types;that of type-Ⅳ is interstitial material micropore type.