Determination Of Petrophysical And Mechanical Properties Interrelationship For Simulated Sands

Abstract

In the evaluation of a petroleum reserve, it is necessary to determine accurately certain petrophysical properties such as porosity and permeability of the reservoir rocks. These properties are affected by the relevant mechanical properties. Such mechanical properties affect also the drilling programs and the development plans for a reservoir. It is more convenient to use homogenous rock samples with nearly constant initial permeability, obtaining such cores is very difficult. In this paper a simulated natural and homogeneous compacted sandstone rock with known mechanical and petrophysical properties were used. The mechanical properties include grain size, cementing material concentration, and compaction (confining) pressure. The effect of these properties on the petrophysical properties of Rock such as permeability and porosity were also known. For the same simulated natural sandstone rocks, Sound wave velocity was measured using an ultra sound tool. Good relationships have been developed between sound wave velocity and other rock properties; porosity, permeability, cementing condition at different confining pressures. The sandstone cores have been grouped according grain size to five groups ranged between 45 and 300 µm mixed with different concentrations of cementing material. The mixture was compacted at three different compaction pressure ranges from 11000 to 23000 psi. These varying lithification factors gave these sandstone rocks a wide range of petrophysical and mechanical properties. The results of this study were presented as graphs of simulated lithification factors, porosity, and permeability versus sound wave velocity