Observations of the Impacts of Millimeter‐ to Centimeter‐Scale Heterogeneities on Relative Permeability and Trapping in Carbonate Rocks

Abstract

The scaleup of CO 2 storage underground to mitigate climate change will require accurate forecasts of the flow behavior of CO 2 in subsurface reservoirs (Boot-Handford et al., 2014;Edenhofer et al., 2014). Flow in the subsurface is often controlled by geological heterogeneity with length scales ranging from micrometers to kilometers. This is particularly the case for carbonate reservoirs which hold more than half of the world's hydrocarbon reserves and have significant storage potential (Sayers, 2008). Reservoir heterogeneity poses challenges to modeling of the fluid flow and is considered a leading cause of difficulties in simulating observed plume migration at a number of industrial and pilot CO 2 storage projects (Cavanagh & Nazari-

Experimental characterization of $${\text {H}}_2$$/water multiphase flow in heterogeneous sandstone rock at the core scale relevant for underground hydrogen storage (UHS)

“…The steady-state relative permeability of the hydrogen and water phase can be calculated based on the one-dimensional form of the extended Darcy’s law and the assumption of constant capillary pressure throughout the core 31 , i.e., Here, the subscript i indicates either the water or the hydrogen phase, is the phase injection rate [ /s], A is the surface area of the inlet of the core [ ], k is the permeability [ ], is the phase relative permeability [–], is the phase viscosity [Pa s], and the pressure drop [Pa] across length L [m]. Relative permeability is a function of saturation.…”

“…Another approach is to measure these parameters directly during core-flood tests in the laboratory 14 , 15 , 17 . Relative permeability can be measured directly using unsteady 27 , 28 and steady-state 15 , 17 , 29 – 31 core-flood test techniques. Capillary pressure curves for the /water/rock system can be derived from MICP data of small rock samples and using the Young-Laplace equation to convert the data from the Hg/air to the /water system 14 , 18 .…”

Simulating Core Floods in Heterogeneous Sandstone and Carbonate Rocks

“…Previously acquired experimental datasets using five rock cores were studied, with experimental methods and data reported in Reynolds and Krevor (2015); Reynolds et al (2018); Manoorkar et al (2021). These data sets comprise observations from corefloods performed on two sandstones and three carbonate rock samples.…”

“…For the sandstones we use the experimental coreflood data of Reynolds and Krevor (2015); Reynolds et al (2018) and for the carbonate rocks, the dataset of Manoorkar et al (2021).…”

“…(2018) and for the carbonate rocks, the data set of Manoorkar et al. (2021). The sandstones exhibit distinctly orientated planar bedding, whereas the carbonates are characterized by isotropic cementation of varying length scale.…”