Due to gravity, drilling cuttings are easily accumulated in an inclined well section, ultimately forming a bed, which places the drill pipe under strong friction torque. In severe cases, this can cause dragging, stuck drills, and broken tools. Because conventional fluids difficult prevent formation of sections, method carrying with pulsed fluid improve wellbore cleanness is proposed. Experiment...

Abstract The wellbore instability of the deep coal seam has always been a difficult problem limiting drilling engineering in Dibei area Tarim basin, China. Therefore, mechanisms and anticollapse countermeasures are investigated this study. Firstly, microstructure physical chemical properties rock studied to analyze mechanism. In addition, orthogonal cleat model 3 Dimension Distinct Element Code...

agricultural crops and food materials exert frictional forces on agricultural machinery elements and on storage walls during their harvest, transportation, processing and storage. coefficient of friction is an important parameter to be predetermined in designing equipments and evaluating processes. an assessment of the coefficient of friction for agricultural materials is usually done through s...

Polyrotaxane metal-organic frameworks (PMOFs) have attracted considerable attention due to their aesthetic topologies and potential biological applications. In this paper, we synthesized two kinds of hcb networks with nanoscale macrocycles. The hcb networks interlocked with each other in inclined and parallel interlocking modes respectively, giving rise to two new PMOFs, {[Ni(DPDBT)(bdc)]·(H2O)...

Gas volume fraction and velocity profiles: vertical and inclined bubbly air-water flows Original Citation Lucas, Gary (2006) Gas volume fraction and velocity profiles: vertical and inclined bubbly air-water flows. Users may access full items free of charge; copies of full text items generally can be reproduced, displayed or performed and given to third parties in any format or medium for person...