Influence of Rock Permeability and Asphaltene Content of Crude Oil on Pore Volume Compressibility: An Experimental Approach

Abstract

Variation of pore volume compressibility has been considered very important for petroleum reservoir engineering as well as rock mechanics. The major goals of this experimental study were to asses the influences of rock permeability and asphaltene content of crude oil on pore volume compressibility using a capillary pressure technique. For the goals of the study to be achieved, three groups of core samples were used. Capillary pressure measurements were carried out and the reduction in pore volume was measured and used to calculate pore volume compressibility. The first group included five core samples of similar permeability, while the second one used five core samples of different permeability. The third group included core samples of similar permeability, which were flooded with crude oils of different asphaltene content. The results indicated that reservoir rocks of similar permeability provided similar values and influence on pore volume compressibility, while rocks of different permeability showed higher values of capillary pressure and pore volume compressibility for higher permeability cores. Furthermore, an increase in the asphaltene content of the crude oil increased the pore volume compressibility for the same resultant reduction in the pore volume of Berea sandstone. The application of the results of this study is expected to have real impact on quantification of the reduction in reservoir rock pore volume and pore volume compressibility and also in considering the stress effect in simulation studies.