Simultaneous Measurements of Relative Permeability, Capillary Pressure, and Electrical Resistivity with Microwave System for Saturation Monitoring

Accurate relative permeability (k(r)) and capillary pressure (P-c) data are essential for predicting the performance of hydrocarbon reservoirs. Traditionally, k(r) and P-c are measured independently in different experimental systems, and rarely on the same samples under identical conditions. However, because these properties can be very sensitive to the same variables, simultaneous measurements are needed for consistency and for rigorous modeling. It is also important to have the capability to establish field-observed initial water saturations in laboratory tests because relative permeability and capillary pressure during imbibition rely on the values of the initial water saturations. A novel apparatus has been constructed to allow simultaneous measurements of capillary pressure, relative permeability, and electrical resistivity on cores up to 2" diameter and 6" long. Fluid saturation profile is monitored by a state-of-the-art microwave technique. A microwave scanner moves along the core, and in-situ fluid saturation is calculated from the transmitted signal intensity. This method does not require tagging fluids which may affect wetting properties. The apparatus can reduce water saturation to a low initial value and can operate at moderate temperature, overburden stress, and fluid pressure. It is equipped with an in-line viscometer for continuous and accurate monitoring of oil viscosity. In this paper, the unique features of the apparatus is presented, along with some capillary pressure and relative permeability data measured simultaneously at elevated temperature and pressure for illustration.