Development of a numerical workflow based on μ-CT-imaging for the determination of capillary pressure-saturation-specific interfacial area relationship in two-phase flow pore-scale porous media systems: A case study on Heletz sandstone

Abstract

Abstract. In this case study, we present the implementation of a FEM-based numerical pore-scale model that enables to track and quantify the propagating fluid-fluid interfacial area on highly complex μ-CT obtained geometries. Special focus is drawn to the reservoir specific capillary pressure (pc)- wetting phase saturation (Sw)- interfacial area (awn)- relationship. The basis of this approach are high resolution μ-CT images representing the geometrical characteristics of a georeservoir sample. The successfully validated two-phase flow model is based on the Navier-Stokes equations, including the surface tension force in order to consider capillary effects for the computation of flow and the phase field method for the emulation of a sharp fluid-fluid interface. In combination with specialized software packages, a complex high resolution modeling domain could be obtained. A numerical workflow based on REV-scale pore size distributions is introduced. This workflow aims at the successive modification of model and model setup for simulating such a type of two-phase problem on asymmetric μ-CT-based model domains. The geometrical complexity is gradually increased starting from idealized pore geometries until complex μ-CT-based pore network domains, whereas all domains represent geostatistics of the REV-scale core sample pore size distribution. Finally, the model could be applied on a complex μ-CT-based model domain and the pc-Sw-awn relationship could be computed.

Exploring residual CO2 trapping in Heletz sandstone using pore‐network modeling and a realistic pore‐space topology obtained from a micro‐CT scan

“…The exhibited ranges of effective porosity, 2 intrinsic permeability, and tortuosity of the sandstone were 0.189-0.219 3 , 325-3070 mD, and 1.31-2.6, respectively, depending on the method of analysis. 28 A mesh of the CT-scanned pore space from Tatomir et al 28 used in Peche et al 29 , was also used in this study (Fig. 1).…”

Nonhysteretic Capillary Pressure in Two‐Fluid Porous Medium Systems: Definition, Evaluation, Validation, and Dynamics

“…Experimental data could then be generated for the true capillary pressure, saturation, and fluid‐fluid interfacial area for a large number of states accurately and precisely under equilibrium conditions with the results interpreted in an inclusive and robust manner. These conditions have been compromised in certain respects in virtually all studies (Chan & Govindaraju, ; Chen et al, ; Joekar‐Niasar & Hassanizadeh, ; Karadimitriou et al, ; Peche et al, ). In effective experiments, the need exists for high‐resolution imaging that requires extended periods of time to capture the range of media considered, the size of the systems investigated, the number of states that can be observed, the time allowed for equilibrium to be achieved, and in many cases the monitoring of interfacial curvature needed to compute the true capillary pressure.…”

“…Many attempts conclude that the HG hypothesis is appropriate and helpful, although some have concluded that only a reduction in hysteretic behavior can be achieved by including interfacial area in the relation (Cheng et al, ; Held & Celia, ; Joekar‐Niasar, Prodanovic, et al, ; Karadimitriou et al, ; Porter et al, ). The issue is considered open and work has continued over recent years using consistently improving methods (Godinez‐Brizuela et al, ; Nikooee et al, ; Paustian, ; Peche et al, ; Sivanesapillai et al, ).…”

Pore-scale tomography and imaging: applications, techniques and recommended practice

“…The paper by Peche et al (2016) and Henkel et al (2016) present a novel workflow for the determination of the interfacial surface area of a CO 2 -brine system as a case study on Heletz sandstone, and additionally a comparison of modeling results with an experimental CO 2 study. Last but not least, Mukunoki et al (2016) present research of CT investigations of structures in unconsolidated sand, relevant for environmental engineering.…”