CO2-原油体系粘度及其预测模型的研究

通过实验和模型计算,研究了CO2-原油体系粘度的影响因素以及相应规律.在相同含水率、CO2注入摩尔分数条件下,体系的黏度随着温度的升高而降低.在一定温度下,压力高于泡点压力时,粘度随压力的减小而减小;压力低于泡点压力时,粘度随压力的减小而增加.油样的粘度计算结果符合相对粘度与CO2注入摩尔分数呈线性关系.与现有的粘度计算模型相比,改进的PR模型考虑的因素更加全面,计算精度更高,可以用于CO2-原油体系粘度的计算.     

带压下原油组分(正十六烷+甲基环己烷+叔丁基苯)三元体系黏度与密度的测量与关联

密度和黏度数据是流体的重要物理性质,原油中主要化合物的密度和黏度数据对于原油流动、热量传递、质量传递等方面有显著影响。研究使用自主研制的落柱式黏度计,并以甲苯和正十六烷作为标准流体对仪器的可靠性和准确性进行了验证。选择正十六烷、甲基环己烷和叔丁基苯分别为原油中长链烷烃、环烷烃及芳香化合物的代表,测定了正十六烷+甲基环己烷+叔丁基苯三元体系在不同温度、压力和浓度下的密度和黏度值。测量的温度范围为318.15~378.15 K,压力范围为2.00~20.00 MPa。结果表明,黏度和密度均随温度升高而降低,随压力升高而升高,且随混合物组成的变化而明显改变。对于黏度数据采用自参考模型进行关联及预测计算,三元体系平均相对绝对偏差AAD关联与预测值分别为2.80%、4.90%。研究得到的原油体系的黏度、密度数据及模型参数,为原油开采及管道运输过程设计、开采技术改造、油藏储量计算等提供了数据支撑。     

海上某油田破乳剂评选及油品性质测试研究

本文针对南海某海上油田下舱油BSW%偏高,且油田进行增产和减水增输作业的问题,在室内对破乳剂进行了破乳剂评选研究;主要考察了破乳剂的类型,加注浓度,油样含水率对脱水性能的影响;另外,测试了油样不同含水率时,黏度与温度的变化关系。结果显示:破乳剂YH-106具有更快的脱水速率和更高的终脱水量,其最佳加注浓度为80mg/L,原油含水率为20%～60%时,破乳脱水均较彻底;粘度测试结果显示:在相同含水率时,黏度随温度升高而降低;在相同温度时,黏度随含水率升高而升高,其中,在温度80℃,含水率60%时,黏度为204.2 mPa·s,所得数据对现场生产具有指导意义。     

聚丙烯及聚苯乙烯发泡体系熔体密度的研究

通过高压毛细管流变仪测量聚丙烯发泡体系的PVT关系,得到一定压力和温度下聚丙烯发泡体系的熔体密度,用于分析发泡体系的毛细管流变特性。与聚苯乙烯和高冲击强度聚苯乙烯发泡体系的熔体密度进行了对比,研究并分析了温度、压力、发泡剂及成核剂含量对发泡体系熔体密度的影响。结果表明:发泡体系的熔体密度均随压力的增大而提高,随温度的升高而降低;在发泡气体的临界压力处,发泡体系的熔体密度产生突变;高压下,发泡剂与成核剂含量对熔体密度的影响很小。     

溶CO2原油乳状液稳定性及界面特性研究

以原油W/O型乳状液为研究对象,利用高压乳状液分水率测定装置、高压流变仪、界面流变仪、显微镜,测试体系分水率随压力(0.5MPa～2.5MPa)的变化、溶气原油乳状液的粘温特性关系、油水界面张力及弹性模量变化、乳状液体系微观形貌,实验结果表明,影响原油乳状液体系破乳效率的主要因素在于油水界面膜强度,体系在溶气状态下较为稳定,不易在热沉降过程中脱出游离水相,其脱出的高含水乳状液相随压力的升高而减少,在较高含水率(40%)时溶CO_2原油乳状液不存在牛顿流体温度区,体相粘度随着温度、压力的上升而降低,初始时界面张力随着压力的升高而增大,稳定后不同压力下的界面张力值相同,界面弹性模量有随压力的升高而增大的趋势。     

长春岭含水原油流变性研究

利用RV22型粘度计,模拟地层条件下流体状态,对长春岭107区和109区3个油样进行了试验研究,测量了不同温度、不同含水率下含水原油粘度,了解原油的流变性,研究结果表明含水原油粘度随含水率变化存在极大值（非乳化拐点）。结论可为油田的开发及原油集输提供科学依据。     

一种新型聚合物熔体动态密度测量方法的研究

介绍一种聚合物熔体在不同温度及压力状态下熔体密度的测量方法,该方法基于聚合物熔体PVT相互关系原理,将测量微距离的读数百分表安装在改进结构的熔体流动速率试验机上,可以测量出任意熔融温度及压力下的聚合物熔体密度。通过对测量结果进行理论分析发现,聚合物熔体密度测量值符合聚合物自由体积理论,即聚合物熔体密度随温度升高而减小,随压力增大而增大。     

热历史对大庆含蜡原油粘弹性的影响

为了研究热历史对大庆含蜡原油粘弹性的影响,结合原油流变学理论,借助小振幅振荡剪切实验对大庆喇嘛甸油田含蜡原油进行粘弹性研究~0。结果表明:热历史是影响喇嘛甸油田原油粘弹性的主要因素。在牛顿回升温度下,实验原油油样的储能模量与耗能模量变化趋势相同,均发生了增大,只是增大的幅度不同,油样的粘弹性增强;在非牛顿回升温度下(高于测量温度),实验原油油样的储能模量与耗能模量变化趋势相同,均发生了减小,只是减小的幅度不同,油样的粘弹性减弱。且非牛顿回升温度越低,储能模量与耗能模量的值减小的幅度越大,粘弹性特征也越弱。     

乙酸乙酯-异丙醇混合液的密度和折光率

常压下测定了乙酸乙酯-异丙醇二元混合液在293.15—318.15 K下的密度和折光率,建立了该二元混合液密度与组成和温度关系的计算方程。计算了过量摩尔体积、折光率偏差,分别用Redlich-Kister方程进行了关联。过量摩尔体积在全摩尔分数范围内为正值,而折光率偏差为负值,且均随温度升高而偏差增大。利用Lorentz-Lorenz关系式计算了二元体系的摩尔折光率和摩尔折光率偏差,偏差亦随温度升高而增大。     

低渗透油藏CO_2驱最小混相压力实验研究

本文利用细管法研究了J区块原油与CO2最小混相压力,为J区块低渗透油藏CO2驱注入压力选择提供依据,应用Anton Paar MCR301旋转流变仪测定了该区块脱气原油粘温性。研究结果表明,原油的粘度对温度非常敏感,随温度升高而大幅度降低。该油藏原油与CO2最小混相压力是22.39MPa,结合该区块地面、地下实际情况,J区块油藏注CO2驱替可以实现混相。     

Viscosity profile prediction of a heavy crude oil during lifting in two deep artesian wells

It has been known that the productivity of artesian wells is strongly dependent on the rheological properties of crude oils.This work targets two deep artesian wells (＞5000 m) that are producing heavy crude oil.The impacts of well conditions including temperature,pressure and shear rate,on the crude oil rheology were comprehensively investigated and correlated using several empirical rheological models.The experimental data indicate that this heavy oil is very sensitive to temperature as result of microstructure change caused by hydrogen bonding.The rheological behavior of the heavy oil is also significantly impacted by the imposed pressure,i.e.,the viscosity flow activation energy (Eμ) gently increases with the increasing pressure.The viscosity-shear rate data are well fitted to the power law model at low temperature.However,due to the transition of fluid feature at high temperature (Newtonian fluid),the measured viscosity was found to slightly deviate from the fitting data.Combining the evaluated correlations,the viscosity profile of the heavy crude oil in these two deep artesian wells as a function of well depth was predicted using the oilfield producing data.     

Experimental studies and discrete thermodynamic modeling on supercritical CO2 extractions of a hexadecane and crude oil

Continuous multiple-contact experiments using a supercritical CO₂ were performed to study the phase equilibrium behavior of the dynamic extractions of a hexadecane and crude oil. The extraction yields increased as CO₂ density increased with a pressure rise at constant temperature. The rates of extractions were also greater at higher pressure. The simulated distillation analysis of extracted crude oil samples represented that the earlier extracts contained lighter compounds and the latter extracts contained progressively heavier compounds. These compositional changes occurring during a dynamic extraction were also ascertained by phase-equilibrium flash calculations using the equations of state and a pseudo-component lumping method. Two different equations of state, Soave-Redlich-Kwong and Peng-Robinson, were used to predict the equilibrium compositions of the extract phase that is a supercritical carbonic phase. The results of phase behavior calculations established the nature of the extraction and partitioning process as a function of time. These results also provided reasonable agreement between the experimental data and the calculated values.     

Upgrading Siberian (Russia) crude oil by hydrodesulfurization: Kinetic parameter estimation in a trickle-bed reactor

Hydrodesulfurization(HDS) of sour crude oil is an effective way to address the corrosion problems in refineries and is an economic way to process sour crude oil in an existing refinery built for sweet oil.Siberian crude oil transported through the Russia-China pipeline could be greatly sweetened and could be refined directly in local refinery designed for Daqing crude oil after the effective HDS treatment.In this study,the HDS of Siberian crude oil was carried out in a continuous flow isothermal trickle-bed reactor over Ni-Mo/γ-Al_2 O_3.The effects of temperature,pressure and LHSV were investigated in the ranges of 320-360℃,3-5 MPa and 0.5-2 h~(-1),keeping constant hydrogen to oil ratio at 600 L·L~(-1).The HDS conversion could be up to 92.89% at the temperature of 360℃, pressure of 5 MPa,and LHSV of 0.5 h~(-1), which is sufficient for local refineries(84%).A three phase heterogeneous model was established to analyze the performance of the trickle-bed reactor based on the two-film theory using Langmuir-Hinshelwood mechanism.The order of sulfur component is estimated as 1.28,and the order of hydrogen is 0.39.By simulating the reactor using the established model,the concentration of H_2, H_2 S and sulfur along the catalyst bed is discussed.The model is significantly useful for industrial application with respect to reactor analysis,optimization and reactor design,and can provide further insight of the HDS of Siberian crude oil.     

Unit cell variations of polyethylene crystal with temperature and pressure

The unit cell dimensions for the drawn and the extended chain crystal samples of polyethylene (PE) have been measured at temperatures between 20° and 130°C under hydrostatic high pressures up to 4000 kg/cm², by the use of high pressure and high temperature X-ray diffraction apparatus. A clear difference was found in the variation of a, b and c dimensions of orthorhombic unit cell in PE with temperature and pressure. The temperature changes of linear compressibility for each axis direction of the unit cell and for cell volume were determined on the bases of the variation of cell dimensions. For the a-axis direction, a drastic increase of the compressibility was observed above ～90°C but for the b- and c-axis directions, it was constant for all the temperature region of the measurement. The values of Grüneisen constant, γ, were evaluated at various temperatures from the compressibility data for both samples. The value of γ of the ECC sample was nearly constant below 90°C and gradually increased above 90°C; in the drawn sample, however, a rather steep increase was observed above 90°C.     

大庆某低渗轻质油藏注空气低温氧化反应动力学研究

轻质油藏注空气提高采收率的机理之一是在油藏中发生低温氧化反应,低温氧化反应进行的程度将对油藏注空气开发的可行性产生决定性的影响。通过在RUSKA2370-601PVT筒中进行的大庆某低渗油田原油与空气恒温恒压氧化反应实验数据,获得轻质油藏注空气低温氧化反应动力学参数为:原油氧化反应为零级反应;21 MPa,87℃时氧化反应的速度常数KO2为1.2255×10-4mol/(mL.h),21 MPa,127℃时氧化反应的速度常数KO2为7.0101×10-4mol/(mL.h),原油样品的阿仑尼乌斯活化能Ea为52.1 kJ/mol。     

线性回归法在常减压装置操作中的应用

通过线性回归的方法,对常减压装置运行过程中原油在进电脱盐前的温度、拔头油进常压炉前的温度和与之相关的物流数据点采集的数据进行回归计算,如果物流的流量对温度影响较大,则能回归成直线;如果物流的流量对温度影响较小,则不能回归成直线。运用这些关系在不影响产品质量的情况下调整操作后,原油在进电脱盐前的温度和拔头油进常压炉前的温度都比调整前有了显著的提高,从而即提高了产品质量,又降低了装置能耗。     

BHD海上稠油注聚破乳剂的研制与应用

针对影响JZ93油田原油脱水的三个因素：聚驱返出、流程初始温度低、段塞流,研制了以酚胺树脂A为起始剂、以MDI交联改性的破乳剂BHD,并成功应用于现场。结果表明,破乳剂BHD使现场的加注浓度由220mg／L下降到170mg／L,且各级原油处理器含水均有所降低,解决了现场的原油脱水问题,减轻了以上三种因素对JZ9—3原油脱水的影响。     

Upgrading Siberian (Russia) crude oil by hydrodesulfurization in a slurry reactor: A kinetic study

Hydrodesulfurization (HDS) of sour crude oil is an effective way to address the corrosion problems in refineries, and is an economic way to process sour crude oil in an existing refinery built for sweet oil. In the current study, the HDS of Siberian crude oil was carried out in a slurry reactor. The Co-Mo, Ni-Mo, and Ni-W catalysts supported on γ-Al₂O₃ were compared at the temperature of 340℃ and the pressure of 4.5 MPa. The HDS activity follows the order of Co-Mo > Ni-Mo > Ni-W at a high concentration of H₂S, and the difference between Co-Mo and Ni-Mo becomes insignificant at a low concentration of H₂S. The influence of reaction temperature 320-360℃ and reaction pressure 3-5.5 MPa was investigated, and both play a positive role in the HDS reaction. A kinetic model over Ni-Mo/Al₂O₃ in the slurry reactor was established. The activation energy is estimated as 60.34 kJ·mol^-1; the orders of sulfur components and hydrogen partial pressure are 1.43 and 1.30, respectively. The kinetic parameters are compared with those in a trickle-bed reactor, implying that the mass transfer is greatly enhanced in the slurry reactor. The back mixing effect is present in the slurry reactor and can be reduced by a multi-stage design, which would lead to higher reactor efficiency in industrial application.     

表面积效应对不同性质原油热力学行为影响研究

针对轻、重质油油藏注空气开发机理,选取典型轻、重质油样进行热重实验,采用改进的Ozawa-Flynn-Wall等转化率法对比分析了不同性质原油三种氧化阶段的热行为和动力学特征,同时探讨了表面积效应对轻、重质原油氧化反应的影响。研究表明：①各氧化阶段之间存在过渡区域,转化率的准确选取对动力学参数至关重要。②轻、重质原油不同氧化阶段的氧化特征存在明显差异,轻质油以低温氧化为主,燃料沉积和高温氧化不显著,且低温氧化、燃料沉积、高温氧化阶段的起始温度更低,更易诱发氧化反应;重质油燃料沉积和高温氧化显著,氧化反应速度更快。③表面积效应导致轻质油低温氧化活化能降低15%以上,峰值温度降低7~17℃。重质油燃料沉积和高温氧化显著增强,燃尽温度下降10~17℃。     

CFD simulation of acoustic cavitation in a crude oil upgrading sonoreactor and prediction of collapse temperature and pressure of a cavitation bubble

In acoustic cavitation, high pressure and temperature are generated due to cavitation bubble collapse in the liquid bulk around the bubble which causes physical and chemical changes in the liquid. In this study, pressure distribution in water caused by ultrasonic wave propagation in a sonoreactor was investigated. Active cavitation zones were determined by calculating acoustic pressure threshold for cavitation inception and compared with experimental results. Collapse pressure and temperature were predicted 3000 atm and 3200 K, respectively, for crude oil at temperature of 25 °C by evaluating cavitation bubble dynamics in the exerted acoustic field. As a consequence, the huge amounts of energy generated by this phenomenon can be applied for changes in oil properties and crude oil upgrading.