PETROPHYSICAL PROPERTIES OF SOME CARBONATE ROCKS AT ABU ROASH AREA, EGYPT  MOHAMED I. SAYED AHMED and ESSMAT A. ABU EL-ANWAR Geological and Geophysical Sciences Dept. National Research Center, P.O. Box 12622 Dokki, Cairo, Egypt. Forty specimens of mudstone, wackestone and dolostone facies representing some Upper Cretaceous carbonate rocks exposed at Abu Roash area, Western Desert, Egypt, were tested to demonstrate their petrophysical properties. The obtained data revealed that the rocks are slightly porous to semi porous, weak to medium strong, very brittle to brittle and of low modulus ratio to average modulus ratio. In dry state the rock specimens exhibit electrical resistivity much higher than those under saturated state. The stress- strain curves were plotted and discussed. The relations between the ultimate compressive strength and electrical resistivity versus the effective porosity, apparent specific gravity and calcium carbonate content were interpreted and expressed by empirical equations.