Imaging the distribution of porosity, permeability, and fluid phases is important to understanding single and multiphase flow characteristics of porous media. X-ray computed tomography (CT) has emerged as an important and powerful tool for non-destructive imaging because it is relatively easy to apply, can offer fine spatial resolution and is adaptable to many types of experimental procedures and flow conditions. This paper gives an overview of CT technology for imaging multiphase flow in porous media, the principles behind the technology and effective experimental design. By critically reviewing prior work using this important tool, we hope to provide a better understanding of its use and a pathway to improved analysis of CT-derived data. Because of the wide variety of image processing options, they are discussed in some detail.

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Although there are a number of mathematical modeling studies for carbon dioxide (CO 2 ) injection into aquifer formations, experimental studies are limited and most studies focus on injection into sandstone reservoirs as opposed to carbonate ones. This study presents the results of computerized tomography (CT) monitored laboratory experiments to analyze permeability and porosity changes as well as to characterize relevant chemical reactions associated with injection and storage of CO 2 in carbonate formations. CT monitored experiments are designed to model fast near well bore flow and slow reservoir flows. Highly heterogeneous cores drilled from a carbonate aquifer formation located in South East Turkey were used during the experiments. Porosity changes along the core plugs and the corresponding permeability changes are reported for different CO 2 injection rates and different salt concentrations of formation water. It was observed that either a permeability increase or a permeability reduction can be obtained. The trend of change in rock properties is very case dependent because it is related to distribution of pores, brine composition and thermodynamic conditions. As the salt concentration decreases, porosity and the permeability decreases are less pronounced. Calcite deposition is mainly influenced by orientation, with horizontal flow resulting in larger calcite deposition compared to vertical flow.

This study showed significant associations between total duration of breast-feeding and BMD. In conclusion, total duration of breast-feeding might be an important risk factor besides age, weight, and years since menopause in postmenopausal osteoporosis.

Fractures play an important role in geothermal reservoir engineering as they dominate the fluid flow in the reservoir. Because of this reason determination of fracture permeability is very important to predict the performance of the geothermal reservoir. A fracture is usually assumed as a set of smooth parallel plates separated by a constant width. The absolute permeability of a smooth-walled fracture is related to the fracture aperture using the cubic law. However, the flow characteristics of an actual fracture surface would be quite different, affected by tortuousity and surface roughness. Though several researchers have discussed the effect of friction on flow, a unified methodology for studying flow on a rough fracture surface has not emerged. As experimental methods are expensive and time consuming most of the time numerical methods are used. In this work, we present results of the numerical computations for single phase flow simulations through two-dimensional synthetically created fracture apertures. These synthetic rock fractures are created using different fractal dimensions, anisotropy factors, and mismatch lengths that are obtained from the producing geothermal reservoirs in South Western Turkey. Lattice Boltzmann Method, which is a new computational approach suitable to simulate fluid flow especially in complex geometries, was then used to determine the permeability for different fractures. Regions of high velocity and low velocity flow were identified. The resulting permeability values were less than the ones obtained with the cubic law estimates. It has been found that as the mean aperture-fractal dimension ratio increased permeability increased. Moreover as the anisotropy factor increased permeability decreased with a second order polynomial relationship.

Sequestration of carbon dioxide in geological formations is an alternative way of managing extra carbon. Although there are a number of mathematical modeling studies related to this subject, experimental studies are limited and most studies focus on injection into sandstone reservoirs as opposed to carbonate ones. This study describes a fully coupled geochemical compositional equation-of-state compositional simulator (STARS) for the simulation of CO 2 storage in saline aquifers. STARS models physical phenomena including (1) thermodynamics of sub-and supercritical CO 2 , and PVT properties of mixtures of CO 2 with other fluids, including (saline) water; (2) fluid mechanics of single and multiphase flow when CO 2 is injected into aquifers; (3) coupled hydrochemical effects due to interactions between CO 2 , reservoir fluids, and primary mineral assemblages; and (4) coupled hydromechanical effects, such as porosity and permeability change due to the aforementioned blocking of pores by carbonate particles and increased fluid pressures from CO 2 injection. Matching computerized tomography monitored laboratory experiments showed the uses of the simulation model. In the simulations dissolution and deposition of calcite as well as adsorption of CO 2 that showed the migration of CO 2 and the dissociation of CO 2 into HCO 3 and its subsequent conversion into carbonate minerals were considered. It was observed that solubility and hydrodynamic storage of CO 2 is larger compared to mineral trapping.

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The effect of microwave irradiation on the recovery of three different oil shale samples was studied. To enhance the microwave efficiency, three different iron powders (Fe, Fe 2 O 3 , and FeCl 3 ) and their three different doses (0.1, 0.5, and 1% by weight, each) were added to the samples as microwave receptors. The doses of each receptor were optimized for each oil shale sample based on the highest oil or gas production value obtained experimentally. During the experimental studies, the temperature distribution and the emissions of CO, H 2 S, CH 4 , and O 2 gases were recorded. Temperature distributions obtained experimentally were modeled analytically to find the microwave power absorption coefficient of each oil shale sample. Experimental and analytical studies show that, oil recovery from oil shales is not only related to reaching the pyrolysis temperature, but also to the amount of time that temperature is maintained. Therefore, for the efficient recovery of oil shales, the best solution is found in a hybrid utilization of irradiation and conventional heat transfer: microwave heating for a rapid temperature rise and conventional heating for sustaining high temperatures effectively.