According to the variations in permeability and grain size mid value obtained from rook cores and well log

the second oil bearing set of the third member of Shahejie Formation in Lendong region

western Liaohe Depression could be divided into positive rhythm(A)

reverse rhythm(B)

composite rhythm(C)

homogeneous rhythm(D) 4 heterogeneous models and 20 sub-type models.Within 4 sedimentary microfacies

models A

C

D hold the highest percentage in Ⅳ

Ⅱ

Ⅲ and Ⅰ facies respectively

whereas model B shows little difference in microfacies. From facies Ⅰ to facies Ⅳ

the thickness of sand gravel stone decreases

the content of argillaceous rock increases

grain size mid-value gets smaller and the permeability becomes bigger.The variation coefficient of permeability and heterogeneity increases from facies Ⅰ to facies Ⅲ

but that of facies Ⅳ is the smallest.