3D Visualization of Film Flow During Three-Phase Displacement in Water-Wet Rocks via Microtomography Method

Spatial image resolution has limited previous attempts to characterize the thin film flow of oil sandwiched in-between gas and water in a three-phase fluid system This paper describes how a systematically designed displacement experiment can produce imagery to define the film flow process in a 3D pore space of water-wet sandstone rocks. We image multiphase flow at the pore scale through three displacement experiments conducted on water-wet outcrop rock with variable spreading tendencies. The experiment has been formulated to observe the relationship between fluid spreading, phase saturations, and pore-scale displacement mechanisms. We provide exhaustive evidence of the three-phase fluid configurations that serve as a proxy mechanism assisting the fluid displacement process in a three-phase system, which includes the oil sandwiches in-between water and gas, the flow of oil via clay fabrics, and the double-displacement process that generates oil and water film in 3D pore spaces. Further, we show evidence that the stable thin-oil film has enhanced the gas trapping mechanism in the water-wet rocks. We observed that the oil layer had covered the isolated and trapped gas blobs, enhancing their stability. As a result, the trapped gas in the positive and zero spreading systems is slightly higher than in the negative spreading system due to a stable oil film. We analyze the Euler characteristic of the individual fluid phases and the interface pair of the fluids during waterflooding, gas injection, and chase water flooding. The comparison of the Euler characteristic for the connected and disconnected fluid phases between three different spreading systems (i.e., positive, zero, and negative) shows that the oil layer's connectivity is highest in the positive spreading system and lowest in the negative spreading system. The oil layer in the positive spreading system is also thicker than in the negative spreading system.

MHD Powell–Eyring dusty nanofluid flow due to stretching surface with heat flux boundary condition

A steady MHD boundary layer flow of Powell–Eyring dusty nanofluid over a stretching surface with heat flux condition is studied numerically. It is assumed that the fluid is incompressible and the impacts of thermophoresis and Brownian motion are taken into regard. In addition, the Powell–Eyring terms are considered in the momentum boundary layer and thermal boundary layer. The dust particles are seen as to be having the same size and conform to the nanoparticles in a spherical shape. We obtain a system of ordinary differential equations that are suitable for analyzed numerically using the fourth-order Runge–Kutta method via software algebraic MATLAB by applying appropriate transformations to the system of the governing partial differential equations in our problem. There is perfect compatibility between the bygone and current results when comparing our numerical solutions with the available data for values of the selected parameters. This confirms the validity of the method used here and thus the validity of the results. The influence of some parameters on the boundary layer profiles (the velocity and temperature for the particle phase and fluid phase, and nanoparticle concentration) is discussed. The results of this study display that the profiles of the velocity for particle and fluid phases increase with increasing Powell–Eyring fluid parameter, but reduce with height in magnetic field values. Mass concentration of the dust particles decreases the temperature of both the particle and fluid phases. The results also indicate the concentration of nanoparticle contraction as Schmidt number increases.

Model-derived uncertainties in the calculation of geological phase equilibria

<p>Phase equilibrium modelling offers a welcome window onto rock-forming processes. It underpins the principles of geothermobarometry, which today is commonly carried out via pseudosection calculations in software such as THERMOCALC and Perple_X. Increasingly, phase equilibrium modelling is combined with complementary approaches such as diffusion or geodynamical calculations, in order to simulate Earth processes.</p><p>However, as anyone with experience of pseudosection calculations will know, it is not always easy to make sense of a rock through phase equilibrium modelling. Problems may relate to: (1) in what way the assumption of thermodynamic equilibrium may, or may not, be applied; (2) uncertainties in compositional analysis; and (3) uncertainties in the composition-dependent equations of state (<em>x</em>-eos). The <em>x</em>-eos are the building blocks of the modelling – one <em>x</em>-eos is needed to represent each of the mineral and fluid phases in the calculation. </p><p>Of the problems listed above, (3) is the most opaque for the user. In this talk I will discuss the uncertainties associated with the <em>x</em>-eos, and the implications of those uncertainties for thermobarometry and the simulation of Earth processes. I will describe two tools, currently in development, for investigating <em>x</em>-eos-derived uncertainty in thermobarometry.</p>

Monodisperse drops templated by 3D-structured microparticles

The ability to create uniform subnanoliter compartments using microfluidic control has enabled new approaches for analysis of single cells and molecules. However, specialized instruments or expertise has been required, slowing the adoption of these cutting-edge applications. Here, we show that three dimensional–structured microparticles with sculpted surface chemistries template uniformly sized aqueous drops when simply mixed with two immiscible fluid phases. In contrast to traditional emulsions, particle-templated drops of a controlled volume occupy a minimum in the interfacial energy of the system, such that a stable monodisperse state results with simple and reproducible formation conditions. We describe techniques to manufacture microscale drop-carrier particles and show that emulsions created with these particles prevent molecular exchange, concentrating reactions within the drops, laying a foundation for sensitive compartmentalized molecular and cell-based assays with minimal instrumentation.