Multiphysics Monitoring of Capillary, Electrical, and Elastic Responses During Drainage and Imbibition at Reservoir Conditions

Abstract

Capillary pressure‐saturation relationships are crucial for geo‐energy recovery, and increasingly, for environmental applications. However, for reservoir‐relevant pressure and temperature conditions, only limited data sets are available from special core analysis in laboratory (SCAL) studies. Complementary measurements, such as electrical resistivity and P‐ and S‐wave velocities, provide geophysically measurable indicators of saturation and fluid distribution, and are essential for interpreting field and borehole data, especially when they are obtained under reservoir‐specific conditions. These properties also offer valuable insights into fluid dynamics in porous multiphase systems, informing predictions of flow and trapping behavior in natural reservoirs, groundwater systems, or soil remediation contexts. Here we present a novel experimental platform, designed for measuring capillary pressure in combination with electrical resistivity and P‐ and S‐wave velocities on rock cores under simulated reservoir conditions. The set‐up allows to determine the physical parameters for both drainage and imbibition cycles and was tested for the brine‐ system using two sandstones with contrasting pore structures. Additionally, contact angles were measured under corresponding conditions to provide further insight into wetting stability. We show that pore geometry primarily controls fluid distribution, connectivity, and capillary trapping, while moderate contact angle changes indicate that wettability is not strictly static. The integration of multi‐physics measurements allows identification of isolated ganglia, continuous brine pathways, and patchy versus homogeneous saturation patterns, providing a robust tool for advancing both laboratory and field‐scale understanding of multiphase flow under reservoir conditions.