multiphase flow

Most of the reactions that occur in microreactors take place on the surface, so it is important to keep the reactants close to the reactive wall. One effective technique in this field is the single-phase hydrodynamic focusing. However, this method has a drawback: a high percentage of reactants penetrate into the sheath fluid. To address this issue, the concept of the two-phase hydrodynamic focusing is introduced in this study. The main idea is to use a highly viscous sheath fluid to create a barrier against reactant penetration into the sheath flow. To demonstrate the effectiveness of this method, a 3D numerical simulation was performed with an irreversible second-order reaction. The results show that the two-phase hydrodynamic focusing increases reaction rates, particularly in downstream regions where the Sherwood number can increase by several orders of magnitude with the use of a highly viscous sheath of liquids. Additionally, it was observed that the use of the two-phase hydrodynamic focusing improves the efficiency, which is defined as the ratio of the solute in the sample flow to the total solute in each cross-section..

Oil extraction from weak sandstone formations that fails under changing in situ stresses leads to fine migration in near wellbore regions. Companies use selective completion practices or downhole filters to control particle production in oil wells. However, fines with various size dispersions will always remain that cause erosion damage in crude oil pipelines. Particles influence oil viscosity as well as density therefore impact flow regime rather than pressure drop in various depths. In this work, we employ Fluent software to simulate particle transport with the multiphase flow in the annulus that models cutting extraction during drilling rather than pipes which simulates the production process. We further estimate damage due to erosive flow under different flow regimes via adjusting various dissimilar particle dispersion functions. Results show erosion damage is at its highest value since a thin film of liquid slurry with high particle concentration forms near the inner wall pipe in the annular flow regime. Outcomes also illustrate that at high drill pipe rotation rates, flow conflicts therefore erosion damage in the annulus increases significantly.

With significant increase of tomographic equipment power, demand for Prediction relative permeability prediction Predicting in porous media from digital image data. In this work, it is predicted three -phase relative permeabilities with co-applying Darcy’s and Stokes equations in two case studies, namely Bentheimer sandstone and Estaillades limestone which their micro-CT data files were downloaded from Imperial College website. In order to perform calculations firstly we extracted pore connected network from the micro-CT data and it is estimated fluids distribution within pore channels during two-phase flow. Then we calculated pressure distribution of each phase solving its continuity and momentum equations within the obtained connected phase network. Pressure distribution and fixed volumetric flow rate ( that flows through all cross-sections perpendicular to the supposed flow direction), then were applied to solve for effective permeabilities. Effective permeabilities were then related to the relevant saturation and curves of two -phase relative permeabilities were derived in this manner. Stone’s equation was finally applied to estimate three phase permeability ternary curves. Results showed that application of correlations for determining fluid distributions is accurate enough for multiphase relative permeability estimation in real case studies. This paper also shows that performing calculations on the segmented REVs is more accurate than work on simplified pore network models extracted from micro-CT data.