Thermal conductivity of partially saturated microstructures Peyman Mohammadmoradi * , Arash Behrang, Saeed Taheri, Apostolos Kantzas Chemical and Petroleum Engineering Department, University of Calgary, Canada article info Article history: Received 12 August 2016 Received in revised form 12 September 2016 Accepted 26 October 2016 abstract The growing importance of tight reservoirs exacerbates the necessity of pore-scale studies to charac- terize porous media from the pore-level point of view. Accurate prediction of pore-scale effective thermal and electrical conductivities leads to proper thermophysical and petrophysical characterization of partially saturated media. In this paper, a numerical framework is offered to predict electrical and thermal conductivities of two-phase saturated microstructures. The immiscible displacement scenarios within the microporosities are conducted utilizing a direct pore morphology-based technique; a set of rules to construct the fluid-fluid interfaces under capillary-driven flows. Subsequently effective thermal and electrical conductivity curves are predicted using steady state diffusion equation. Two sets of mi- crostructures are used as the pore space geometries; real and synthetic. The real media under consid- eration include binary images of oil/water-wet sandstone and carbonate formations and the fluid systems contain steam-oil and water-oil equilibriums. The swelling spheres algorithm is adapted to generate two-dimensional granular synthetic media based on a typical particle size distribution of Alberta's unconsolidated oil sand. The result packages, including thermal diffusivity and conductivity, electrical conductivity, formation factor, and apparent diffusion coefficient are generated and discussed considering rock types and fluid configurations. The thermal and electrical conductance of well- connected consolidated microstructures appear to be weak functions of water saturation and are mainly controlled by porosity and solid phase configuration. © 2016 Elsevier Masson SAS. All rights reserved. 1. Introduction Pore-level characterization of porous media matters because the hydrocarbon is trapped in pores and must be produced from there. In this regard, petrophysical and thermophysical characterization of partially saturated media is beneficial in a number of engineering applications such as well logging, utilization of thermal oil recovery methods, geothermal projects, hydro-geological studies, drilling and fluid mechanics. All of these processes demand accurate knowledge of solid and multiphase fluid configurations inside the pore space which are used to predict high-temperature and high- pressure thermal and electrical behavior of the partially saturated pore-level structures. Accurate determination of electrical proper- ties, mostly affected by fluids configuration, saturation history, and rock wettability, leads to lower uncertainty associated with the dynamic reservoir simulation and a detailed understanding of formation thermophysical behavior is important for efficient modeling of heat transfer phenomena and reliable designing of thermal processes. To perform most of the thermal processes utilized in enhanced oil recovery, a knowledge of the heat transfer in porous media is required. An effective transfer of heat results to significant changes in viscosities and surface tensions and consequently improves the ultimate recovery factor. The effective thermal conductivity (ETC) and effective thermal diffusivity are two important parameters that are generally used to determine how well heat can transport in a porous medium. In heterogeneous porous materials, ETC generally depends on pore space morphology, porosity, and saturation. Mostly, the measurements of the ETC of rock materials are per- formed by optical scanning, laser-flash analysis [15,16], the tran- sient technique [30,63,83] and guarded hot plate [1,2,4]. In addition to the experimental techniques, there are numerous methods to predict thermal properties of porous media either theoretically and numerically or by coupling experiments with computational modeling [9]. It is also tried to train artificial neural networks using experimental data and predict ETC models [25,70]. The vast ma- jority of theoretical approaches are limited to single-phase satu- rated porous media; a solid fabric saturated by a fluid, e.g. water * Corresponding author. 2500 University Dr NW, Calgary, AB T2N 1N4, Canada. E-mail address: seyedpeyman.mohammad@ucalgary.ca (P. Mohammadmoradi). Contents lists available at ScienceDirect International Journal of Thermal Sciences journal homepage: www.elsevier.com/locate/ijts http://dx.doi.org/10.1016/j.ijthermalsci.2016.10.019 1290-0729/© 2016 Elsevier Masson SAS. All rights reserved. International Journal of Thermal Sciences 112 (2017) 289e303