H. Eltom+*, O. Abdullatif*, M. Makkawi* and A. Abdulraziq*
* King Fahd University of Petroleum and
+ corresponding author email: email@example.com, firstname.lastname@example.org
This study investigates microporosity in an outcrop
analogue of the Upper Jurassic (Kimmeridgian) Arab-D
carbonate reservoir in central
Microporosity and associated permeability in the analysed samples (n = 125 for porosity and n = 61 for permeability) range from 0.11% to 4.8 % and 0.36 to 4.35 mD, respectively. Three types of microporosity were observed: (i) between macro- and micro-sparry calcite crystals; (ii) between micrites of varying morphologies; and (iii) within macro-sized dolomite crystals. Microporosity distribution was controlled by sparry calcite cement, micrite crystal size, sorting and shape, and the presence of dolomite crystals.
Statistical analyses of microporosity and associated permeability show non-normal distributions for both variables. Coefficients of variation indicated high variability for porosity and permeability, which may be attributed to the high degree of heterogeneity in the pore system. In general there was a poor correlation between microporosity and permeability, but the correlation improved when visualized for individual textural groups.
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