the main task of drilling the formation by the bit is done via scraping, crushing and grinding. discharging the fluid from the bit nozzles is done with high pressure which assists to break the rocks. different parameters affect the bit selection and design for each drilling formation, but the most important one is drillability that depends on hardness of the formation. in this paper, the design...

We explore the possibility of preparation of Pt3M (M = Fe, Ni and Co) nanocubes using carbon monoxide as an alternative protocol under different experimental conditions. The results suggest that the sole carbon monoxide flow at ambient pressure can enable the formation of binary Pt-M nanocrystals, but it is inadequate to facilitate the formation of Pt3M nanocubes in the given system under speci...

To simulate the effect of free st ream turbulence on turbulent spot formation, experiments were conducted on the interaction of localized three-dimensional disturbances with the harmonic waves in a laminar boundary layer on a flat plate. Experiments conducted in three-dimensional diverging flow (but zero pressure gradient) show, while individually the disturbances decay downstream, their intera...

in this research, process asymmetric polyetherimide hollow fiber membranes using ethanol (0, 2 and 4 wt%) as non-solvent additive in the polymer dope via phase inversion method were fabricated. aqueous solution of 1-methyl-2-pyrrolidine (nmp) (90%) was applied as a bore fluid to avoid inner skin layer formation and water was used as the external coagulant. the morphology of fabricated membranes...

introduction climate is a system consisting of atmosphere, lithosphere, cryosphere, hydrosphere, and biosphere. this system is involved in the exchange of energy and moisture among these five components. the exchanges link the atmosphere as the central component of the climate to other spheres. changes do not occur separately in this system; rather change in one component contributes to reactio...

An intensive experimental investigation was conducted to study the effect of vertical tail, single and twin (with different cant angles) on the flow field and the corresponding aerodynamic forces and moments of a model of a fighter A/C. Aerodynamic forces under different flight conditions and different vertical tail settings were measured in a supersonic wind tunnel. Furthermore, effects of ver...

introduction the study area is located in the shurab area that is about 50 km southeast of qom. volcanic rocks of the shurab area have basaltic composition that is associated with salt and marl units. igneous rocks of the shurab area have not been comprehensively studied thus far. clinopyroxene composition of volcanic rocks, and especially the phenocrysts show magma chemistry and can help to id...

gas hydrate formation in production and transmission pipelines and consequent plugging of these lines have been a major flow-assurance concern of the oil and gas industry for the last 75 years. gas hydrate formation rate is one of the most important topics related to the kinetics of the process of gas hydrate crystallization. the main purpose of this study is investigating phenomenon of gas hyd...

Abstract. This paper deals with a two-phase compressible gas-liquid model relevant for modeling of gas-kick flow scenarios in oil wells. To make the model more realistic we include a natural pressure-dependent well-formation interaction term allowing for modeling of dynamic gas influx/efflux. More precisely, the interaction between well and surrounding formation is controlled by a term of the f...