Measurement of rock-core capillary pressure curves using a single-speed centrifuge and one-dimensional magnetic-resonance imaging.
Capillary pressure curves are widely used in materials, soil, and environmental sciences, and especially in the petroleum industry. The traditional (Hassler-Brunner) interpretation of centrifugal capillary pressure data is based on several assumptions. These assumptions are known to lead to significant errors in the measurement of capillary pressure curves. In this work, we propose a new "single-shot" method to measure the capillary pressure curve of a long sedimentary rock core using a single-speed centrifuge experiment and magnetic-resonance imaging to directly determine the water saturation distribution along the length of the sample. Since only a single moderate centrifuge speed is employed, the effect of gravity can be ignored and the outlet boundary condition of the core plug was maintained. The capillary pressure curve obtained by the single-shot method is remarkably consistent with results determined with conventional mercury-intrusion methods. The proposed method is much faster and more precise than traditional centrifuge methods.
Magnetic Resonance Imaging (MRI) Centre, Department of Physics, University of New Brunswick, P.O. Box 4400, Fredericton, New Brunswick, E3B 5A3, Canada.
Quan
Q
Chen
Bruce J
BJ
Balcom