Emulsification of Indian heavy crude oil using a novel surfactant for pipeline transportation

The most economical way to overcome flow assurance problems associated with transportation of heavy crude oil through offshore pipelines is by emulsifying it with water in the presence of a suitable surfactant.In this research,a novel surfactant,tri-triethanolamine monosunflower ester,was synthesized in the laboratory by extracting fatty acids present in sunflower（Helianthus annuus）oil.Synthesized surfactant was used to prepare oil-in-water emulsions of a heavy crude oil from the western oil field of India.After emulsification,a dramatic decrease in pour point as well as viscosity was observed.All the prepared emulsions were found to be flowing even at 1°C.The emulsion developed with 60%oil content and 2wt%surfactant showed a decrease in viscosity of 96%.The stability of the emulsion was investigated at different temperatures,and it was found to be highly stable.The effectiveness of surfactant in emulsifying the heavy oil in water was investigated by measuring the equilibrium interfacial tension（IFT）between the crude oil（diluted）and the aqueous phase along with zeta potential of emulsions.2wt%surfactant decreased IFT by almost nine times that of no surfactant.These results suggested that the synthesized surfactant may be used to prepare a stable oil-in-water emulsion for its transportation through offshore pipelines efficiently.

CO2 emission of urban passenger transportation in China from 2000 to 2014

This study reviewed the urban passenger transportation(UPT)development of seven typical cities in China from 2000 to 2014,estimated the UPT CO2emission,analyzed the structure,and discussed the main factors of UPT CO,emission.Results showed that increases of GDP,population,and UPT scale of the cities have speeded up.The most significant development of UPT is that the growth of private vehicles is greatly faster than that of public transportation.The total and per-capita UPT CO2 emissions both increased.The share of private vehicles emission to total UPT CO2emission has increased,with the share in range of 65%-88%in 2014,exponentially leading to the increases of total and per-capita UPT CO2 emission.Although UPT CO2 emission structure with more share of public transportation would slow down the UPT CO2emission increase,private vehicle CO2 emission is recognized as the dominated driving factor.Contributions of driving factors,such as GDP,population,private vehicle CO2 emissions,to UPT CO2 emission are different among the cities.Private vehicle CO2 emission.is the dominated factor for UPT CO2emission in Beijing and Taiyuan.Besides private vehicle CO2emission,GDP also plays an important role in UPT CO2emissions of Chengdu,Shanghai,Guangzhou,and Urumqi.Contributions of private vehicle CO2 emission and GDP to UPT CO2 emission are almost same in Xi'an.

Study on characteristics of pipeline transportation and sulfur fixing of cleaned coal logs

As special cylindrical briquettes of coal for long distance pipeline transportation and directly cleaned combustion the cleaned coal logs should possess two characteristics of transportation in pipeline and cleaned combustion. In order to make cleaned coal logs a rational technology for manufacturing, cleaned coal logs was designed and compound sulfur fixing binders with high effects of binding and sulfur-fixing was selected and combined. In addition, by means of characteristic experiments of strength, wear, waterproof and sulfur-fixing five different cleaned coal logs made with different compound sulfur fixing binders in different compaction conditions was tested and measured. Experimental results indicated that the manufacturing technology of cleaned coal logs was reasonable and the combination of compound sulfur fixing binders was scientific. Cleaned coal logs made up with the fourth group of coal mixture had high strength, good waterproof property, efficient sulfur-fixing, good characteristic of transportation, and achieved the performance requirement for pipeline transportation and sulfur fixing.

Main Indexes of Pipeline Transportation of Crude Oil and Gas

ＭａｉｎＩｎｄｅｘｅｓｏｆＰｉｐｅｌｉｎｅＴｒａｎｓｐｏｒｔａｔｉｏｎｏｆＣｒｕｄｅＯｉｌａｎｄＧａｓ￥／／Ｎｏｔｅ：Ｔｈｅｔｏｔａｌｌｅｎｇｔｈｏｆｃｒｕｄｅａｎｄｇａｓｐｉｐｅｌｉｎｅｒｅａｃｈｅｄ１７５８７ｋｍ，ｉｎｃｌｕｄｉｎｇ９２７２ｋｍｏ...

Experiment and mechanism of dynamic drag reduction in pipeline transportation

Based on the analysis of the disadvantages of traditional methods in reducing pipeline resistance, the new conception of dynamic drag reduction in pipeline transportation has been proposed. The experimental results and mechanism of dynamic reduction of pipeline resistance were also discussed in detail. The main conclusion is that the dynamic reduction of resistance exerts forces on the moving materials along both the radial direction and the axial direction. The radial force throws the materials upwards to depart from the pipe wall to reduce the frictional force, while the axial force directly reduces the resistance by providing the force to overcome the drag.

CO2驱配套地面工艺技术研究现状

CO2驱油是油田提高采收率的重要手段之一,开展对CO2驱油配套地面工艺全过程(CO2的捕集、管输、增压及回注)的系统梳理与总结,有利于明确其关键技术问题,以推广该技术的应用。对CO2捕集工艺而言,须明确各工艺方法的适用性,深入研究多法联用技术以适应工况的变化;根据所建膜分离和化学吸收法联合捕集工艺的模拟,表明该工艺方案可以实现对含高浓度CO2产出气中CO2的富集提纯以利于CO2的循环注入工艺。对CO2管道输送工艺而言,根据应用PR方程所开展的含杂质CO2物性参数计算结果,明确了杂质种类、杂质含量以及沿线温度压力变化对CO2物性参数的影响不可忽略,选用精度高的物性计算方法,关注杂质对管输CO2相态及物性参数的影响至关重要;根据应用商用PIPESIM软件所建立的CO2管输工艺模型计算结果,指出在水力热力计算结果上所开展的参数优化须充分考虑各种因素对运行参数的影响,以期得到更优的计算结果。对CO2增压工艺而言,在相平衡控制和预处理基础上开展的增压设备选型是保证该工艺经济可行的关键。对CO2回注工艺而言,完善的注入增压技术的应用须重点关注气体组成。最后,给出了CO2驱配套地面各关键环节工艺设计的建议。

含杂质CO2管道输送泄漏扩散的数值模拟

在全球变暖形势下,减轻温室气体排放所造成的气候变化是21世纪全人类面临的巨大挑战。碳捕获、利用与封存(CCUS)作为一项极具潜力和环境效益的应对全球气候变化的新兴技术,成为全球研究的焦点。管道中输送的含杂质CO2流体不可预见的泄漏和扩散,会对人类和动物构成潜在的生理危害并造成巨大的经济损失。基于某油田含杂质CO2特定管段泄漏点的扩散数值模拟研究,应用计算流体动力学(CFD)方法分析了高压CO2流体泄漏后CO2浓度的扩散规律和压力云图响应,在此基础上做出安全警示建议,以便定量分析与评价含杂质CO2管道输送的安全性,为预防及解决CO2流体泄漏问题提供理论依据。

稠油注CO2降黏管道输送技术研究进展及展望

通过调研稠油注超临界CO2管道降黏输送技术研究现状,分析目前研究中存在的问题,明确今后研究方向,可为稠油管道输送技术研究提供参考。目前国内外学者对超临界CO2在稠油中溶解特性、超临界CO2降低稠油黏度规律、室内环道实验、注超临界CO2稠油工艺技术经济模拟计算等进行了研究,结果表明,注超临界CO2工艺技术与加热、掺稀等传统稠油降黏输送工艺相比,在运行能耗和输送成本方面具有较大优势,但目前主要还是室内研究,距工业化应用还有很大差距,还需进一步在CO2与稠油相互作用的微观机理、溶解后与稠油的混相流动规律、溶解在稠油中的CO2在管输过程中的逸出问题、稠油溶解CO2腐蚀问题、输送工艺设计和终端CO2的分离回收工艺等方面加强研究。

超临界CO2管道安全输送距离敏感性分析

为保障超临界CO2管道安全、高效运行,有必要研究超临界CO2管道安全输送距离。以长庆油田超临界CO2管道工程为例,对含杂质CO2流体的相态特性及物化性质进行计算分析,确定超临界CO2管道的最低运行压力和最低运行温度;改变管径、高程差与地温设计参数,调整入口温度与输量运行参数,计算不同条件下超临界CO2管道输送距离,分析在输送距离范围内的压降梯度和流速变化。结果表明:影响输送距离的主要因素为入口温度、地温及输量,综合考虑输送距离和管道压降,为使CO2在输送过程中处于超临界态运行,在管道设计时,选择管道路由应尽量避开上坡段,管径为250 mm较合适;在管道运行时,输量控制在1~1.5 Mt/a,出口温度不宜高于60℃。对不同入口压力进行经济性分析,当入口压力为13 MPa时,CO2管道运输成本最低,为29.57元/t,通过经济优化得出管道输送距离为177.6 km。

管输超临界CO2泄漏过程管内瞬变特性研究

CO 2输送是整个CCUS技术中重要的中间环节,而管道输送则是超临界CO 2最高效和最经济的输送方式。为了研究超临界CO 2泄压过程中管内节点温度、压力和相态的变化,针对管道泄漏工况,利用OLGA软件对不同初始压力、温度和流量对泄放过程中管段内不同节点的温度、压力等参数和CO 2的相态变化的影响进行模拟和分析。分析结果表明:泄漏发生时,输送压力越低,管道泄漏口处的温度越低,应在设计时考虑管道的耐低温能力;初始输送温度对管输压降和流量变化影响不大,主要影响管内温度,进而影响CO 2的相态变化。初始温度过高,CO 2易在泄漏过程中转为气态,对管道造成冲击;初始温度过低,管道温降加快,更易产生干冰,两种情况均会对管道造成损伤。针对超临界CO 2管道输送系统,应考虑泄漏过程中减压波的传递对泄漏口裂纹扩展的影响。所得结果可为我国CCUS技术的发展提供理论支持。

PVA/PVP blend polymer matrix for hosting carriers in facilitated transport membranes: Synergistic enhancement of CO2 separation performance

CO2 separation performance in facilitated transport membranes has been reported depended not only on the CO2 carrier properties but also to a great extent on the polymeric matrix regarding the capacity of retaining water and carriers as well as the processability for coating defect-free ultra-thin films. In this study, the blends of hydrophilic polymers polyvinyl pyrrolidone(PVP) and polyvinyl alcohol(PVA) were studied to find an optimal polymer matrix to host carriers in facilitated transport membranes for enhanced CO2 separation. It is found out that the optimized blend is 50/50 PVA/PVP by weight, which shows a significant increase in the water uptake(from 63 to 84%) at equilibrium state compared to the neat PVA. Polyethyleneimine(PEI) was employed to provide sample carriers to evaluate the synergistic effect of PVA and PVP on the CO2 separation performance. A thin film composite(TFC) membrane of the optimized blend(50/50 PVA/PVP with 50 wt% PEI) was fabricated on polysulfone(PSf) porous support. The fabrication of the TFC membranes is simple and low cost, and CO2 permeance of the optimized blend membrane is nearly doubled with the CO2/N2 selectivity remained unchanged, showing great potential for industrial applications of the resulted membranes.

含杂质超临界CO2输送管道的停输影响因素

CO2管道输送和安全运行相关技术的研究是CCUS技术推广的重要一环。在年生产36万吨CO2的陕西延长油田CCUS项目基础上,对管道输运含杂质超临界CO2的过程进行研究。在分析延长油田实际含杂质CO2物性及相图的前提下,采用OLGA软件分析超临界CO2稳态输送过程,进而研究超临界CO2管道停输及安全停输的影响因素,分析停输过程中流体达到准临界区的脉动规律,及初始温度、流量参数对CO2管道停输的影响,获得初始条件对脉动冲击的影响规律。

Investigation of the performance of CF3I/c-C4F8/N2 and CF3I/c-C4F8/CO2 gas mixtures from electron transport parameters

CF3I gas mixtures have attracted considerable attention as potential environmentally-friendly alternatives to SF6 gas,owing to their excellent insulating performance.This paper attempts to study the CF3I ternary gas mixtures with c-C4F8 and buffer gases N2 and CO2 by considering dielectric strength from electron transport parameters based on the Boltzmann method and synergistic effect analysis,compared with SF6 gas mixtures.The results confirm that the critical electric field strength of CF3I/c-C4F8/70%CO2 is greater than that of 30%SF6/70%CO2 when the CF3I content is greater than 17%.Moreover,a higher content of c-C4F8 decreases the sensitivity of gas mixtures to an electric field,and this phenomenon is more obvious in CF3I/c-C4F8/CO2 gas mixtures.The synergistic effects for CF3I/c-C4F8/70%N2 were most obvious when the c-C4F8 content was approximately 20%,and for CF3I/c-C4F8/70%CO2 when the c-C4F8 content was approximately 10%.On the basis of this research,CF3I/c-C4F8/70%N2 shows better insulation performance when the c-C4F8 content is in the15%–20%range.For CF3I/c-C4F8/70%CO2,when the c-C4F8 content is in the 10%–15%range,the gas mixtures have excellent performance.Hence,these gas systems might be used as alternative gas mixtures to SF6 in high-voltage equipment.

超临界-密相CO2管输特性模拟计算研究

目前,我国的超临界-密相CO2管道输送技术还处于起步阶段,缺乏理论依据和技术支撑。针对这一问题,以某油田特定的气源组分为例,采用PR状态方程,得到了含杂质的CO2相态图,相态图中出现了明显的气液两相区,临界点温度为30.76℃,压力为7.54 MPa。以100×10^4 t/a的输量为基础,针对不同管径条件下沿程压力、温度、密度的变化,选择DN300为超临界-密相输送的最佳管径,对不同入口压力、温度条件下的管输参数进行模拟。结果表明,高压状态下压降几乎不受温度影响,密度对压力和温度数据敏感,黏度对压力数据敏感。超临界-密相CO2在输送过程中,应避免进入准临界区和气液两相区,尽量保持高压运行。

新型抗CO2缓蚀剂的开发及其在原油集输管道中的应用

针对西部某油田含CO2原油集输管道腐蚀现象严重的问题,以不饱和脂肪酸、三乙烯四胺和氯苯甲烷为原料合成了一种咪唑啉型缓蚀剂,并将咪唑啉型缓蚀剂与非离子表面活性剂进行复配研制出一种新型抗CO2缓蚀剂KW-101。考察了含水率、温度、流速以及CO2分压对缓蚀率的影响,室内试验结果表明:随着含水率、温度、流速和CO2分压的增大,缓蚀剂KW-101的缓蚀率逐渐降低,当试验温度为50℃、流体含水率为80%、流速为3 m/s、CO2分压为1.5 MPa时,缓蚀率仍可以达到80%以上。现场应用结果表明:在含CO2原油集输管道中注入200 mg/L的缓蚀剂KW-101后,挂片的腐蚀速率可以降低至0.006 mm/a,达到了良好的缓蚀效果。

含气体杂质超临界CO2管道输送特性研究

CO2管道输送是碳捕集利用与封存(CCUS)过程中的一个重要环节。对诸如从高含CO2的天然气等烃类中捕集的CO2,所含杂质组分主要为CH4,根据标准设定组分杂质含量,用PR方程计算不同杂质含量的CO2多元体系的物性参数。结果表明,在一定温度压力下,密度和黏度会发生突变,比热容会出现极值,与纯CO2对比,在CO2中加入杂质改变物性突变位置。设定甲烷的物质的量分数为1%,其他杂质SO2、He、H2、CO、N2、O2、Ar、N2、C2H6和H2S物质的量分数分别为1%、3%和5%,利用HYSYS计算CO2三元体系的管输参数,发现除SO2外其他杂质使超临界CO2管道输送压降增加,H2S对管道输送压降影响很小,H2和He对管道压降影响较大,气体杂质对超临界CO2管输温降基本没有影响。因此,在管道运行过程中,应尽量避免CO2中H2杂质的存在。所得结果为超临界CO2管道设计和安全高效运行提供科学依据。

Sacrificial piles as a countermeasure against local scour around underwater pipelines

Local scour around pipelines crossing rivers or in marine environments is a significant concern.It can lead to failure of the pipelines resulting in environmental side effects and economic losses.This study developed an experimental method to reduce local scour around pipelines with a steady flow of clear water by installing cylindrical and cubical sacrificial piles.Three sizes of sacrificial piles were examined in a linear arrangement.Sacrificial piles were installed on the upstream side of the pipeline at three distances.Maximum scour depth reduction rates below the pipeline were computed.The results showed that sacrificial piles could protect a pipeline from local scour.A portion of scoured sediment around the sacrificial piles was deposited beneath the pipeline.This sediment accumulation reduced the scour depth beneath the pipeline.Analysis of the experimental results demonstrated that the size of piles(d),the spacing between piles,and the distance between the pipe and piles(Xp)were the variables that reduced the maximum scour beneath the pipeline with a diameter of D.For the piles with d=0.40D and 0.64D,X_(p)=4OD was the optimal distance to install a group of piles,and cubical piles could mitigate scour more effectively than cylindrical piles under similar conditions.For the piles with d=D,the greatest reduction in scour depth was achieved at X_(p)=50D with any desired spacings between piles,and cylindrical piles in this dimension could protect the pipeline against scour more effectively than cubical piles.

Experimental and Finite Element Analysis of Corroded High-Pressure Pipeline Repaired by Laminated Composite

Repairs of corroded high-pressure pipelines are essential for fluids transportation under high pressure.One of the methods used in their repairs is the use of layered composites.The composite used must have the necessary strength.Therefore,the experiments and analytical solutions presented in this paper are performed according to the relevant standards and codes,including ASME PCC-2,ASME B31.8S,ASME B31.4,ISO 24817 and ASME B31.G.In addition,the experimental tests are replicated numerically using the finite element method.Setting the strain gauges at different distances from the defect location,can reduce the nonlinear effects,deformation,and fluctuations due to the high pressure.The direct relationship between the depth of an axial defect and the stress concentration is observed at the inner side edges of the defect.Composite reparation reduces the non-linearities related to the sharp variation of the geometry and a more reliable numerical simulation could be performed.

Impacts of CO2 and H2S on the risk of hydrate formation during pipeline transport of natural gas

Evaluation of maximum content of water in natural gas before water condenses out at a given temperature and pressure is the initial step in hydrate risk analysis during pipeline transport of natural gas, The impacts of CO2 and ELS in natural gas on the maximum mole-fractions of water that can be tolerated during pipeline transport without the risk of hydrate nucleation has been studied using our novel thermodynamic scheme. Troll gas from the North Sea is used as a reference ease, it contains very negligible amount of CO2 and no H2S. Varying mole-fractions of CO2 and INS were introduced into the Troll gas, and the effects these inorganic impurities on the water tolerance of the system were evaluated. It is observed that CO2 does not cause any distinguishable impact on water tolerance of the system, but H2S does. Water tolerance decreases with increase in concentration of H2S. The impact of ethane on the system was also investigated. The maximum mole-fraction of water permitted in the gas to ensure prevention of hydrate formation also decreases with increase in the concentration of C2H6 like H2S. H2S has the most impact, it tolerates the least amount of water among the components studied.