Investigating the rheological behavior of Algerian crude oil stemming from station of separation (quagmire)

An experimental study was conducted to investigate the rheological behavior of Algerian crude oil stemming from station of separation (quagmire) of the Tin Fouye Tabankort sector (southern Algeria). The rheological measurements at different temperatures (20°C, 30°C and 50°C) were performed employing AR 2000 rheometer of TA-Instruments. Several parameters such as shear rate, the temperature and the presence of crude oil from another quagmire on the rheological properties have been studied. The experimental results show that the studied crude oil displays non-Newtonian shear thinning behavior at low values of shear rate and a Newtonian behavior at high values of shear rate, which can be best presented by the Casson model. The rheological examination tests (flow and dynamic mode (oscillation)) have shown that the rheological properties of the crude oil were significantly influenced by the temperature and the crude oil addition.     

The effect of cationic surfactant additives on flow properties of crude oil

Pretreatment of the crude oil with flow improver or pour point depressants has received the greatest acceptance due to its simplicity and economy. Three cationic surfactants Bola form based on urea were prepared by quaternization reaction with alkyl dihalides of different chain length (hexayl, decyl-, and dodecyl-dibromide). The prepared compounds (U6, U10, and U12) were evaluated as surface active agents as well as pour point depressant for crude oil compared to monosurfactant (U12a) corresponding to (U12). The surface parameters of each synthesized surfactant were calculated from their surface tension profile including the critical micelle concentration, maximum surface excess (Γ_max), and the minimum surface area (A_min). The free energies of micellization (ΔG°_mic) and adsorption (ΔG°_ads) were also calculated. Its pour point and viscosity decreased significantly after adding surfactants. FTIR studies of crude-surfactant mixture showed remarkable decrease in concentration of viscosity enhancing groups such as alkanes, alcoholic, and acidic groups, indicating the effectiveness of both the surfactants.     

Comparative studies of the rheological behavior and microstructural properties of emulsions (oil/distilled water phase) and (oil/Lias water phase)

Abstract

The rheological behavior of crude oil and their emulsions were investigated as a function of two water types (distilled water and the LIAS water). The focus of this work is to obtain more knowledge about the effect of LIAS water concentration, which used to maintain pressure and produced from production of crude oil in the oil fields Tin Fouye Tabankort-south Algeria, on the rheological properties of crude oil. The rheological parameters were measured by using AR-2000 rheometer at 15?°C under dynamic and shear testing conditions. The measured data were first classified into two groups for Newtonian and non-Newtonian fluids. Depends on the type and concentration of water, the non-Newtonian behavior was described in better way by the Casson, Power law and the Herschel–Bulkley models. The results indicated that the viscosity, the yield stress, the elastic modulus, (G′), the loss modulus, (G″), and the microstructure of the prepared emulsions not only varied with water concentration but also by water types.     

Effects of stress and oscillatory frequency on the structural properties of Daqing gelled crude oil at different temperatures

The structural properties of Daqing gelled waxy crude oil were studied with a controlled-stress rheometer under oscillatory shear mode. Our results demonstrate that the gelled waxy crude oil shows viscoelastic properties. The linear viscoelastic region and yielding of crude oil can be determined not only by the critical linear shear stress (τ_cl) and yield stress (τ_y), but also by the critical linear shear strain (γ_cl) and yield strain (γ_y) respectively. With the decrease of test temperature, τ_cl and τ_y increased greatly while γ_cl and γ_y decreased gradually. The crude oil showed more elastic at lower temperatures. The frequency had little effect on the structure of crude oils in the measured range.     

微观液滴分布对含蜡原油乳状液流变性的影响

通过显微镜观察并拍摄原油乳状液的微观结构图像,研究了乳状液体系分散相液滴大小及分布规律,以及微观液滴分布对乳状液体系流变性的影响机理。W/O型原油乳状液中含水率增加,引起内相液滴个数增多,小液滴所占的比例减小,相对大的液滴所占的比例增大;搅拌转速的增大,使体系内相液滴个数增多,平均液滴直径减小。通过测试在固定搅拌条件下制备的不同含水率的3种含蜡原油乳状液在原油凝点附近温度屈服特性和触变性等流变特性,可以发现随含水率的增大,乳状液体系屈服应力增大、触变性增强,且含水率越高,变化的趋势越明显。通过测试不同搅拌转速下制备的含水率为30% 的原油乳状液在原油凝点附近温度的触变性,可以看出随搅拌转速的增大,体系经受同等剪切速率剪切时对应的剪切应力增大、触变性增强。进一步建立了屈服应力与测试温度、含水率之间的关系式,其平均相对误差为9.83%。     

孤岛油田东区原油流变性研究

重质高粘原油在地层条件下表现为非线性渗流,其流变性测试结果对于指导其油藏的开发具有重要意义。对孤岛油田东区重质高粘原油渗流流变性进行了研究。结果表明,该区含气原油为假塑性流体,地层条件下非线性渗流显著;脱气原油粘弹性较弱;注水开发时,油水井间的水驱速度应控制在0．885m/d以内。     

Rheological modeling and drag reduction studies of Indian heavy crude oil in presence of novel surfactant

Viscosity and rheology modeling of heavy crude oil were studied at different shear rate and temperature with and without naturally extracted surfactant Mahua. Drag reduction analysis was done in 2”-ID, 2.5 m horizontal pipeline at different temperatures and flow rates. Viscosity was reduced by 60.4% after addition of 1000 ppm Mahua at 50°C. Modeling analysis showed that crude oil-surfactant samples followed Power law model with high regression coefficients. Maximum drag reduction of 94.8% occurred after adding 2000 ppm Mahua to 85% heavy oil+15% water at 40°C and at a flow rate of 50 LPM.     

A viscosity bio-reducer for extra-heavy crude oil

Considering that high viscosity of extra-heavy crudes is related to the formation of a dispersed phase of asphaltenes, a dynamic interaction model is proposed which explains the mechanism to achieve viscosity reduction based on the molecular interacting energies between the ester active principle of a viscosity bio-reducer and the asphaltene fraction of crude oil. A qualitative comparison is made between the theoretical and experimental results observed in relation to the rheological behavior of Mexican extra-heavy crudes in the presence of the enhancer. Both, theoretical and experimental data, described a decrease in the asphaltenes dispersed fraction in relation to the ester concentration mainly because of polarity in asphaltenic crudes.     

高效原油脱氯剂的开发及应用

利用原油脱氯反应机理,以合成的N,N二甲基丙二胺、改性β-羟乙基三甲胺、十六胺聚氧丙烯醚三类物质进行复配,制备一种原油脱氯剂。当此三类物质相应的比例分别为20%,79%,1%时,原油中的有机氯化物脱除效果最佳。实验室评价结果表明,当此种脱氯剂加入量为50μg/g,通过电脱盐脱水过程,可以将原油有机氯脱除85%以上,大幅度降低塔顶冷凝水的氯离子含量,脱除有机氯的效果明显。该原油脱氯剂,操作费用低,且无毒无害,使用前景广阔。     

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.     

Experimental investigation of the rheological behavior of algerian crude oils from the quagmires

In this work, the rheological behavior for three types of crude oil coming from different quagmires namely Amassak, Tamendjelt and Tin Fouye of the TFT sector (Tin Fouye Tabankort/South Algeria) has been experimentally investigated. A controlled stress rheometer (AR 2000, TA Instrument) was used throughout this investigation. The experimental measurements in terms of flow and dynamic tests were carried out at different temperatures during the shear rate over the range of 0–700?s^?1 and frequency range of 0.1–10?rad/s. The obtained results show that the viscosity and shear stress of the crude oils decreases about 53.30%, 58.80%, and 59% respectively, when the temperature increased from 10 to 20?°C. The yield stress required to flow of crude oils also decreased to 37.06%, 89.78%, and 77.53% respectively. The dynamic analysis of the crude oils by identifying of the storage modulus (G′) and the loss modulus (G″) has indicated that the rheological properties of crude oils were significantly temperature-dependent.     

单6东超稠油粘温及流变特征研究

稠油流变性的研究对稠油开发方案编制、数值模拟、稠油集输和了解稠油在地下的渗流机理等均是非常重要的。该文以单家寺稠油为例 ,深入研究了超稠油的粘温、剪切变稀和屈服值等流变特性 ,总结出了流变特性与温度的关系式。同时研究了超稠油与周边地区普通稠油和特稠油的流变性差别。从流变性的角度 ,提出了超稠油热采的部分技术要求。     

Effect of organic alkali,n-alkanol,and nonionic surfactant ternary compound system on viscosity reduction of viscous crude oil

To reduce the viscosity of viscous crude oil and flow resistance, the effect of a ternary compound system including organic alkali, n-alkanol, and nonionic surfactants on viscous crude oil viscosity reduction was studied. The results showed that n-alkanol effectively reduced the droplet size of an emulsion and the viscosity of viscous crude oil and improved the fluidity of viscous crude oil. Of the low-carbon n-alkanols, n-pentanol has the best viscosity-reducing effect. The organic alkali avoids the phenomenon of fouling and corrosion caused by inorganic alkali and reacts with the acidic macromolecular components in viscous crude oil to generate alkanolamides, which produce synergistic effects with nonionic surfactants and reduce the interfacial tension between oil and water. In the ternary compound of organic alkali, n-alkanol, and nonionic surfactant, the viscosity reduction effect of viscous crude oil is significantly enhanced compared with that of a single reagent. The viscosity reduction rate of viscous crude oil of the diethanolamine ternary compound system reached 98.1% and was the best choice by experimental validation. It is shown that a reasonable formula of compound system and dosage can significantly reduce the viscosity of viscous crude oil.     

HF-101原油脱钙剂的工业应用

采用大港油田集团油田化学有限公司研制的HF-101脱钙剂对中国石油锦州石化分公司炼油厂掺炼杜巴原油进行了工业试验。应用结果表明:使用HF-101脱钙剂后原油中的钙平均脱除率可达到90.89%,脱后原油的平均钙质量分数为24.81μg/g;原油的灰分由脱钙前的0.065%降至0.030%左右;原油的盐含量和水含量也大幅度下降。锦州石化分公司使用脱钙剂后,满足石油焦和煅烧普通焦的灰分质量要求,经济效益显著,并且使用HF-101脱钙剂可使电脱盐装置的操作电流下降50%,具有较好的节能降耗作用。     

原油含水率测定装置的改进

通过对石油生产行业现行测定原油含水率方法与石油加工行业现行测定原油含水率方法的对比,优化改进出一种新的实验装置,经优化后的实验装置,可通用于石油生产加工行业。     

The rheological properties of abnormally viscous oil

Results of experimental determination of Yaregskoe field degassed oil's rheological characteristics are given in the article. Modern methods of viscoelastic and thixotropic properties research are described and results of these method's application while abnormal oil research are shown. As a result an improved data of Yaregskoe field's oil is obtained and there is a recommendation to extend a number of enhanced oil recovery methods, including physicochemical and wave methods application.     

ZC-11型原油阻降粘剂的工业应用

某单位加工的原油以涠洲、陆丰、西江等海洋油品为主,油品性质复杂,原油中的重质组分易在储罐底部沉积,随着生产周期的增长,罐底积累的油渣造成原油罐区有效库容下降、输送泵故障频发及检修清罐损失等生产难题.企业联合科研院所开发了1种用于防止原油沉降、降低原油粘度、凝固点的阻降粘剂(ZC-11型),工业应用表明,在正常工况下,该...     

大庆原油的粘弹性实验研究

用RSH150控制应力流变仪对大庆原油进行了振荡剪切实验。结果表明,储能模量和耗能模量随测量温度的降低呈指数规律增加;存在使流变性恶化的“最差加热温度”;降温速率越高,测量温度下蜡晶结构强度和胶凝温度越低。在同样的剪切温度下,粘弹性参数和胶凝温度随粘性流动能量耗散增加而急剧降低直至达到稳定状态;在同样的粘性流动能量耗散下,剪切温度越接近测量温度,储能模量和耗能模量越低,胶凝温度越低;当剪切温度接近或超过反常点时,测量温度下的粘弹性参数基本不随剪切温度变化;原油结构在经历剪切后具有不可逆的恢复特性。     

复合驱体系化学剂对原油活性组分界面扩张性质的影响

采用小幅低频振荡方法,研究了复合驱体系化学剂如盐、碱、聚合物以及表面活性剂对原油活性组分界面膜扩张黏弹性质的影响和界面扩张模量及相角的变化趋势。研究结果表明,复合驱体系化学剂对原油活性组分界面膜的性质均有一定影响:盐通过改变活性物质在界面上的吸附而影响界面扩张黏弹性质;聚合物能增大低相对分子量活性组分的界面扩张黏度,对高相对分子量活性组分的影响不明显;碱与原油活性组分反应,使扩张黏度明显变化,界面膜的弹性大大增强;表面活性剂能将高相对分子量活性组分从界面上顶替下来,使界面体现为近似单独表面活性剂的性质,而对于低相对分子量活性组分,界面表现为活性组分与表面活性剂混合吸附膜的性质;扩张模量的相角在高工作频率下出现负值。探讨了表观负相角产生的机理。图9表2参7     

复合驱体系化学剂对原油活性组分界面扩张性质的影响

采用小幅低频振荡方法,研究了复合驱体系化学剂如盐、碱、聚合物以及表面活性剂对原油活性组分界面膜扩张黏弹性质的影响和界面扩张模量及相角的变化趋势.研究结果表明,复合驱体系化学剂对原油活性组分界面膜的性质均有一定影响盐通过改变活性物质在界面上的吸附而影响界面扩张黏弹性质;聚合物能增大低相对分子量活性组分的界面扩张黏度,对高相对分子量活性组分的影响不明显;碱与原油活性组分反应,使扩张黏度明显变化,界面膜的弹性大大增强;表面活性剂能将高相对分子量活性组分从界面上顶替下来,使界面体现为近似单独表面活性剂的性质,而对于低相对分子量活性组分,界面表现为活性组分与表面活性剂混合吸附膜的性质;扩张模量的相角在高工作频率下出现负值.探讨了表观负相角产生的机理.图9表2参7