Characterizing Fluid Presence and Transport in Rock Cores at Reservoir-like Conditions via Spatially Resolved Nmr Relaxation/diffusion Maps

The properties of fluids saturating rocks depend strongly on temperature and pressure. Therefore, ambient laboratory conditions may not be desirable for the investigation of fluids in reservoir rocks. To mimic the reservoir, a pressurized and temperature controlled (overburden) cell, compatible with Nuclear Magnetic Resonance (NMR), was assembled within a 2 MHz NMR Rock Core Analyzer. 1D NMR relaxation and 2D diffusion-relaxation correlation distributions of fluid-saturated rock cores were measured in conjunction with 1D NMR imaging. By performing these spatially resolved NMR relaxometry and diffusometry experiments within the environment of the overburden cell, it is possible to obtain porosity, fluid saturation and residual fluid content profiles under reservoir-like conditions. Here we show for the first time that these spatially resolved NMR relaxometry and diffusometry experiments could be performed under elevated pressures and temperatures for fluids flooding rock cores in the laboratory. Experiments performed with this NMR setup may allow one to study the oil properties under reservoir conditions, which may inform oil recovery enhancement strategies.