FIVE-SPOT INJECTION/PRODUCTION WELL LOCATION DESIGN BASED ON FRACTURE GEOMETRICAL CHARACTERISTICS IN HEAVY OIL FRACTURED RESERVOIRS DURING MISCIBLE DISPLACEMENT: AN EXPERIMENTAL APPROACH

Mapping fracture characteristics by using seismic acquisition and processing is important not only to identify sweet spots, but also to optimize production, especially for unconventional heavy oil reservoirs. In this experimental work we used five-spot micromodels initially saturated with heavy oil to find the optimum well locations during first-contact miscible displacement. The experiments were performed at a fixed injection rate on fractured micromodels with various patterns. The optimum location for injection/production wells was found in the pattern where fractures make an angle of 45° with the mean flow direction. Moreover, oil recovery was increased with the density, length, level of scattering, and discontinuity of fractures. The analysis of the experimentally measured recovery curve revealed that there are three distinct stages for each displacement. The efficiency of the first stage was found to be dominated by dispersion and diffusion. However, the recovery of the second stage was significantly affected by the fracture orientation. The displacement efficiency of the third stage was controlled by solvent dispersion, which is at maximum for the pattern with higher density, length, scattering, and discontinuity of fractures. Saturation monitoring showed that the fracture geometrical characteristics strongly affected the splitting, spreading, and shielding of the produced fingers and solvent front shape and consequently affected the recovery factor. As a result, five-spot micromodels can be used to investigate the optimum location of injection/production wells during miscible displacements in fractured heavy oil reservoirs.     

Optimization of mechanical properties of in situ polymerized poly(methyl methacrylate)/alumina nanoparticles nanocomposites using Taguchi approach

Polymer Bulletin - Alumina nanoparticles are among important metal oxides with specific properties but chemically incompatible with an organic matrix such as poly(methyl methacrylate) (PMMA). In...     

Real-time separation of aerosolized Staphylococcus epidermidis and polystyrene latex particles with similar size distributions

For rapid and effective detection of airborne microorganisms, it is preferable to remove dust particles during the air sampling process because they can reduce the detection accuracy of measurements. In this study, a methodology of real-time separation ofaerosolized Staphylococcus epidermidis (S. epidermidis) andpolystyrene latex (PSL) particles of similar size was investigated. These two species represent biological and non-biological particles, respectively. Due to their different relative permittivities, they grasp different numbers of air ions under corona discharge. After these charged particles enter a mobility analyzer with airflow, in which an electric field is applied perpendicular to the airflow, the S. epidermidis and PSL particles separate, due to the difference in their electric mobilities, and exit through two different outlets. Purities and recoveries for S. epidermidis and PSLat their respective outlets were determined with measurements of aerosol number concentrations and ATP bioluminescence intensities at the inlet and two outlets. The results were that purities for PSL and S. epidermidis were 70% and 80%, respectively. This methodology provides a rapid and simple way to increase the detection accuracy of bacterial agents in air.

Copyright © 2017 American Association for Aerosol Research     

Effect of chemical solvents on the technological characteristics of hemp fibre/polypropylene composites

The effects of different chemical solvents on the technological properties of hemp fibre-reinforced polypropylene composites were evaluated in this experimental work. Composite profiles consisting of hemp fibre and polypropylene at 50% weight ratios, with 2% of coupling agent were fabricated using melt compounding followed by injection moulding. The composite specimens were then immersed in CH₃COOH, HNO₃, H₂SO₄, NaOH, NH₃, and C₆H₅NH₂ for different time intervals. Then, the weight loss and mechanical strength of samples were measured. Results indicated that the chemical reagents had significant effect on the weight loss of the composites. The weight loss ratio of the control samples was lower than that of those samples exposure to the chemical solvents. The tensile strength and modulus, and impact strength of composite specimens decreased after exposure to the chemical solvents. The highest mechanical reduction was observed in the case of NaOH. SEM micrographs showed that the extent of degradation increased in composites when they are exposed to chemical solvents.     

Adsorptive separation of meta-xylene from C8 aromatics

Industrial adsorptive separation process for liquids is most successful when the involved species have very close boiling points, making distillation expensive or are thermally sensitive at convenient distillation temperatures. The adsorption process was studied for separating meta-xylene from a feed mixture containing all C₈ aromatics on binder-free X and Y zeolites in the liquid phase. Zeolitic adsorbents with different SiO₂/Al₂O₃ were synthesized by the hydrothermal method and ion-exchanged with alkaline metal cations like lithium, sodium and potassium. The adsorption process was carried out in a breakthrough system at temperature of 110–160 °C and pressure of 6–8 atm. The influence of adsorbent moisture content on the separation process was studied. The optimization of adsorption process was also investigated by the changing operation conditions. The isotherms for each isomer of C₈ aromatics and the desorbent possess the adsorption characteristics of Langmuir type. The selectivity factor of meta-xylene and the saturation adsorption capacities of adsorbates were determined. It was observed that the selectivity of meta-xylene increased by sodium ion-exchanging of cationic sites in Y zeolite and the selectivity factor of meta-xylene/para-xylene, meta-xylene/ortho-xylene and meta-xylene/ethylbenzene in the optimum conditions was determined to be 2.62, 2.83 and 5.93, respectively.     

Nucleation and growth of Pd nanoparticles during electrocrystallization on pencil graphite

The aim of present study was to investigate the mechanism of palladium electrodeposition on a pencil graphite surface from an aqueous solution containing 1 mM PdCl₂ and 500 mM H₂SO₄. Cyclic voltammetry revealed that the electrodeposition process proceeds via an initial underpotential deposition (UPD) and subsequently, it follows by the overpotential deposition (OPD) under diffusion control. Current transients showed a complex deposition trend, i.e. the electrodeposition of Pd includes at least three stages: adsorption on the surface, and two types of nucleation courses; two-dimensional (2D) and three-dimensional (3D) which limited by the lattice incorporation of Pd adatoms and the diffusion of Pd ions, respectively. Therefore the electrocrystallization of Pd on pencil graphite conforms to the Stranski–Krastanov growth mechanism. Furthermore, theoretical models were applied to evaluate each of above mentioned stages for different electrode potentials and to estimate the electrochemical parameters of Pd electrodeposition. The micrographs of electrodeposited Pd at relatively high frequency of the nucleation rate, illustrated a well dispersed Pd nanoparticles with a relatively narrow size distribution.     

New design equations for assessment of load carrying capacity of castellated steel beams: a machine learning approach

This paper presents an innovative machine learning approach for the formulation of load carrying capacity of castellated steel beams (CSB). New design equations were developed to predict the load carrying capacity of CSB using linear genetic programming (LGP), and an integrated search algorithm of genetic programming and simulated annealing, called GSA. The load capacity was formulated in terms of the geometrical and mechanical properties of the castellated beams. An extensive trial study was carried out to select the most relevant input variables for the LGP and GSA models. A comprehensive database was gathered from the literature to develop the models. The generalization capabilities of the models were verified via several criteria. The sensitivity of the failure load of CSB to the influencing variables was examined and discussed. The employed machine learning systems were found to be effective methods for evaluating the failure load of CSB. The prediction performance of the optimal LGP model was found to be better than that of the GSA model.     

Conservative laparoscopic management of a large cornual ectopic pregnancy

Cornual pregnancy traditionally has been treated with laparotomy and either cornual resection or hysterectomy. Recently, more conservative operations have been developed, and operative laparoscopy has provided yet another management option. This report describes the conservative management of a large cornual ectopic pregnancy and reviews the techniques and outcomes of conservative repair that have been described in the literature.