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Investigation of a solid particle deposition velocity in drag reducing fluids with salinity

Petroleum Research 2024年第3期9卷 347-358页

作者： Chinemerem Obi Mohammad Azizur Rahman Ibrahim Hassan Rashid Hasan Texas A&MUniversity Qatar Texas A&M University CsCollege StationUSA

Optimal and cost-effective drilling operations in extended-reach horizontal wells depend on efficient solid cuttings removal from the *** solids-suspended multiphase processes such as crude petroleum transportation,separation,and processing of oil and gas streams also require the efficient removal of these *** terminal settling velocity(Vts)of the solid particle is a vital parameter that controls the removal efficiency of these *** a drilling scenario when there is a hold on fluid cir-culation such as connection time,the accurate estimation of Vs provides the driller with time available to prevent solid *** severe conditions,this can result in a stuck pipe,especially for extended-reach horizontal *** this work,both spherical and non-spherical particle deposition were experi-mentally investigated in several fluid rheology and *** concentrations(0.1 vol%and 0.05 vol%.)of partially-hydrolyzed polyacrylamide(PHPA)were used as a drag-reducing additive for water-based drilling *** PHPA drag-reducing fluid(reduced pressure loss)acts as a turbulence *** PHPA polymer chain suppresses any turbulence in the flow,reducing the turbulent eddy *** effects of salinity(3 wt.%Nacl and 3 wt.%CaCl_(2) contamination)on solid particle settling velocity(Vs)in drag-reducing fluids were also *** velocity was achieved for all experiments and seemed to increase with increased diameter/***,cases when this trend was not consistent were observed and therefore a new parameter of@(sphericity index×diameter)was pro-posed.V,increases with Q value for all *** drilling,PHPA also aids in sealing the fracture in the *** and without salt in the fluid,how lowering drag affected the settling velocity of solid particles(drill cuttings)could be *** settling velocity tests will be improved in drag-reducing PHPA solutions with the knowledge from this study.

关键词： deposition velocity Drag reducingfluids Salinity Visualization Drilling

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deposition of water-soluble inorganic ions in PM_(2.5) in a typical forestry system in Beijing,China

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Forest Ecosystems 2018年第4期5卷 486-497页

作者： Junqi Ding Xiaoxiu Lun Weifang Ma Lu Zhao Yingying Cao Fengbin Sun Renna Li College of Environmental Science and Engineering Beijing Forestry University State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Academy of Environmental Sciences School of Soil and Water Conservation Beijing Forestry University

Background: Rapid economic development in China has resulted in an increase in severe air pollution in city groups such as the Beijing-Tianjin-Hebei Metropolitan Region. PM2.5(fine particles with an aerodynamic equivalent diameter of 2.5 μm or less) is one of the most important pollutants. The deposition process is an important way of removing particles from the air. To evaluate the effect of an urban forest on atmospheric particle removal, a concentration gradient method was used to measure the deposition velocities of water-soluble inorganics in PM2.5 in two national forest parks in Beijing, China. The following eight water-soluble inorganic ions in PM2.5 were investigated: sodium, ammonium, potassium, magnesium, calcium, chloride, nitrate, and ***: Samples were taken from two sites in Beijing from the 7 th to the 15 th May, 2013. The concentrations of water-soluble inorganic ions were analyzed with ion chromatography. We used the concentration gradient technique to estimate the deposition flux and velocity. To determine the relationships between leaf traits and particle accumulation, typical leaf samples from each selected species were studied using scanning electron ***: The total deposition flux and total deposition velocity during the daytime were higher than those at *** showed the biggest deposition flux and velocity at both study sites, whereas the other ions showed different trends at each site. Result from higher proportion of coniferous to broadleaved trees, the total deposition flux of the eight ions measured in Jiufeng National Forest Park was greater than that in Olympic Forest ***: The deposition velocity was affected by meteorological conditions such as wind speed, temperature,and humidity. The deposition velocity was also influenced by tree species. The surface of plants is an important factor influencing particle deposition. The results of this study may help in assessing the effects of forestry sy

关键词： Fine particle Water-soluble inorganics Forest Dry deposition deposition velocity

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Particle deposition in ventilation duct with convex or concave wall cavity

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Journal of Central South University 2018年第11期25卷 2601-2614页

作者： WANG Fei-fei ZHANG En-shi XU Xin-hua WANG Jin-bo MI Jian-chun School of Environmental Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China College of Engineering Peking UniversityBeijing 100871China

A numerical study is carried out on particle deposition in ducts with either convex or concave wall *** show that,if compared with smooth duct,particle deposition velocitiesVd^+increase greatly in ducts with wall *** specifically,forτ+1,Vd^+grows relatively *** of particle deposition with wall cavities is caused by the following mechanisms,i.e.,interception by the wall cavities,expanded deposition area,and the enhanced flow *** general,addition of wall cavities is contributive for particle deposition,so it provides an efficient approach to remove particles,especially with small size,e.g.,***,the convex wall cavity leads to a larger increment ofVd^+than the concave wall ***,taking pressure loss into account,thoughVd^+is relatively lower,duct with the concave wall cavity is more efficient than that with the convex wall cavity.

关键词： numerical simulation ventilation duct particle deposition deposition velocity

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Evaluation of Data Replacement Strategies for CASTNET Dry deposition Modeling

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Journal of Environmental Science and Engineering(B) 2012年第6期1卷 789-799页

作者： Christopher Rogers Thomas Lavery Kevin Mishoe Ralph Baumgardner AMEC Environment & Infrastructure Inc. Jacksonville FL 32207 USA Fuss & O 'Neill Inc. Providence R102908 USA AMEC Environment & Infrastructure Inc. Newberry FL 32669 USA U.S. Environmental Protection Agency Research Triangle Park NC 27711 USA

The U.S. EPA （Environmental Protection Agency） established the CASTNET （Clean Air Status and Trends Network） and its predecessor, the NDDN （national dry deposition network）, as national air quality and meteorological monitoring networks. Both CASTNET and NDDN were designed to measure concentrations of sulfur and nitrogen gases and particles. Both networks also estimate dry deposition using an inferential model. The design was based on the concept that atmospheric dry deposition flux could be estimated as the product of a measured air pollutant concentration and a modeled deposition velocity （Vd）. The MLM （multi-layer model）, the computer model used to simulate dry deposition, requires information on meteorological conditions and vegetative cover as model input. The MLM calculates hourly Fa for each pollutant, but any missing meteorological data for an hour renders Vd missing for that hour. Because of percent completeness requirements for aggregating data for long-term estimates, annual deposition rates for some sites are not always available primarily because of missing or invalid meteorological input data. In this work, three methods for replacing missing on-site measurements are investigated. These include （1） using historical values of deposition velocity or （2） historical meteorological measurements from the site being modeled or （3） current meteorological data from nearby sites to substitute for missing inputs and thereby improve data completeness for the network＇s dry deposition estimates. Results for a CASTNET site used to test the methods show promise for using historical measurements of weekly average meteorological parameters.

关键词： Dry deposition deposition velocity leaf area index MLM (Multi-Layer Model)

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Diurnal variation of ozone flux over corn field in Northwestern Shandong Plain of China

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Science China Earth Sciences 2014年第2期57卷 503-511页

作者： ZHU ZhiLin SUN XiaoMin DONG YunShe ZHAO FengHua Franz X MEIXNER Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Department of Environmental Geography and Human Health Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences Biogeochemistry Department Max Planck Institute for Chemistry

High concentration ground-level ozone(O3)has adverse effects on plant growth and *** to the O3concentration-based index,the O3flux-based(especially stomatal O3uptake)index has been considered the better criterion for assessing the impact of ozone on vegetation and *** paper reports on a study of O3flux using the eddy covariance technique over a corn field in the Northwestern Shandong Plain of *** variation of atmospheric O3concentration,deposition velocity and flux,and their relationships to environmental factors are *** results show that:(1)During the observation period(9 August–28 September,2011),there was a strong diurnal variation of O3concentration,with low(16.5 nL L?1)and high(60.1 nL L?1)O3mean concentrations observed around 6:30 and 16:00,*** O3concentrations during daytime(6:00–18:00)and nighttime(18:00–6:00)were 39.8±23.1 and 20.7±14.1 nL L?1(mean±std),*** maximum observed concentration was 97.5 nL L?*** concentration was mainly affected by solar radiation and air temperature.(2)Whether daytime or nighttime,ground-level O3flux is always *** diurnal course of mean deposition velocity was divided into 4 phases:a low and stable process during nighttime,fast increasing in early morning,relatively large and steady changes around noon,and quickly decreasing in later *** and nighttime mean deposition velocities were 0.29 and 0.09 cm s?1,*** maximum deposition velocity was 0.81 cm s?*** magnitude of deposition velocity was influenced by the corn growth period,and its diurnal variation was significantly correlated with global radiation and relative humidity.(3)O3flux was affected by variations of both O3concentration and deposition velocity,with mean O3fluxes-317.7 and?70.2 ng m?2s?1during daytime and nighttime,*** was strong correlation between O3flux and CO2flux or latent heat *** comparing the deposition velocities of daytime a

关键词： ozone flux deposition velocity ozone concentration eddy covariance cropland ecosystem Northwestern Shandong Plain

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Screening of the Indoor Plants for Removing Formaldehyde

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Meteorological and Environmental Research 2013年第2期4卷 40-45,48页

作者： Shujuan Zhang Yaotang Huang Zizhao Xie Xulan Zhang School of Environmental Science and Engineering Sun Yat-sen University Environmental Technology Center of Nanhai

[ Objective] The research aimed to screen out the best ornamental houseplants to remove formaldehyde from indoor air through deposition velocity and to explore the pathways of plants for formaldehyde removal. [ Method] Fifty-three indoor ornamental plant species were experimen- ted in series of sealed chambers （volumes of O. 096 m^3 ） by formaldehyde fumigation with the internal concentration of （1 ± 0. 1 ） mg/L in this study. The removal efficiency of formaldehyde was assessed by the uptake fluxes and the deposition velocity of formaldehyde. [ Result] Six species of indoor plants （ Hedera helix, Ficus elastica Roxb. ex Hornem, Nephrolepis exaltata cv. Bostoniensis, Begonia evansiana, Mentha canadensis L. and Adiantum capillus-veneris Linn. ） with high formaldehyde removal efficiency were firstly screened out. Significance analysis of the deposition velocity by Statistical Program for Social Sciences （SPSS） presented that tested plants belonging to the same genera or family had similar ability to remove formaldehyde pollution. The diurnal variations of deposition velocity for the six plants were then tested further. The results showed that four of them, including Ficus elastica Roxb. ex Hornem, Nephrolepis exaltata cv. Bostoniensis, Mentha canadensis L. and Adiantum capi//us-veneris Linn. re- moved formaldehyde mainly by leaves surface adsorption, while Begonia evansiana and Hedera helix by stomatal uptake, f Conclusion Begonia evansiana and Hedera helixare the most efficient indoor plants among the 53 species studied for phytoremediation of the air formaldehyde pollution.

关键词： Formaldehyde pollution Indoor plants Screening deposition velocity Stomatal uptake China

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