AAPG Bulletin, V. 83  (1999), No. 2 (February 1999), P. 230-243.

Lithological and Zonal Porosity-Permeability Distributions in the Arab-D Reservoir, Uthmaniyah Field, Saudi Arabia¹

Salih Saner and Ali Sahin²
 

©Copyright 1999.  The American Association of Petroleum Geologists.  All Rights Reserved
 

¹Manuscript received July 24, 1997; revised manuscript received June 8, 1998; final acceptance July 14, 1998.
²The Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia; e-mail: ssaner@kfupm.edu.sa; asahin@kfupm.edu.sa
 

We acknowledge the support of Saudi Aramco for this work under KFUPM/RI Project No. 21059. We thank F. O. Meyer of Saudi Aramco, who read the manuscript and suggested improvements, and AAPG Bulletin reviewers N. Hurley, J. W. Smocker, and R. A. Clark, who offered constructive remarks. 

ABSTRACT

Permeability vs. porosity plots for the Arab-D carbonate reservoir show a relatively poor correlation, so permeability estimation still remains an issue for discussion. In this study, we integrated basic core measurements with stratigraphic and petrographic analyses to determine porosity and permeability distributions and to identify the association of high permeability, in Darcy range, with lithology and defined reservoir zones.

Carbonate rock types in the Arab-D reservoir have been grouped into three lithofacies: granular, muddy-granular, and muddy. The granular lithofacies is the most porous and permeable, and all permeability measurements in Darcy range are associated with it. The muddy facies is represented by low porosity and permeability values. Porosity and permeability distributions of the muddy-granular facies spread over the two regions representative of the muddy and the granular facies.

Porosity and permeability distribution patterns of the Arab-D zones are controlled by both type and the arrangement of different lithologies. Zones made up of granular facies demonstrate uniformly high porosity and permeability distributions and reveal the highest permeability intervals. Zones represented by muddy-granular and muddy facies indicate more heterogeneous and mostly bimodal porosity and permeability distributions.