Abstract
Representative sandstone samples were collected from the surface-type section of the Shajara Formation of the Permo-Carboniferous Unayzah Group for reservoir characterization through fractal dimension investigation. Two models based on mercury intrusion technique were employed to represent the pores characteristics of these sandstones. The results show that realistic dimensions and outstanding fractal features of porous structures in Shajara sandstones, when these materials are correlated by thermodynamic model and 3-D fractal model of mercury intrusion. On the basis of sub-Unayzah unconformity, sub-Middle Shajara local unconformity, mudstone of the Middle Shajara and sub-Khuff unconformity, the three porous and permeable sandstone units of Shajara Formation were treated separately and classified here into three fractal dimension units. The units from base to top are: Lower Shajara Fractal Dimension Unit, Middle Shajara Fractal Dimension Unit, and Upper Shajara Fractal Dimension Unit. The thermodynamic model and 3-D fractal model were effectively used to characterize the porous structures of Shajara sandstones in logical and quantitative way.