丙烯液相本体聚合过程Polymers Plus建模与分析

依据聚合反应机理,采用ASPEN公司的PolymersPlus为软件平台,对Hypol工艺的丙烯液相本体聚合过程进行建模与流程模拟。聚合体系的物性以及相平衡采用含链扰动的统计流体理论(PC-SAFT)方法计算,参考文献值并结合工业装置的操作数据对丙烯聚合反应机理及其动力学参数进行修正。模拟分析表明,催化剂的氢活化速率常数、催化剂自失活速率常数以及链增长速率常数对单体转化率影响较大;氢气的链转移常数、活性中心向单体的链转移常数以及链增长速率常数对聚合度影响较大;催化体系的多活性中心导致相对分子质量分布加宽,对相对分子质量分布曲线进行解耦得到催化剂的活性位个数为6;反应器温度的变化不仅影响产量,同时也影响产品的相对分子质量。     

恒温差热式流量计影响因素模拟与试验研究

针对恒温差热式流量计在井下测量小流量流体时误差较大的问题,进行了温度、压力的影响研究.根据流量计加热器电功率与被测流体流量的关系,分析了温度对液态水物性参数的影响,通过数值模拟研究了不同温度下水流量与流量计换热功率的变化曲线.在此基础上,搭建了可调节水温和流体流量的试验平台,在定压(常压)条件下,通过试验分析了25～4...     

断裂带流体活动证据的确定——以东营凹陷胜北断裂带为例

运用宏观分析与显微测试等手段,对断裂带周围介质及流体本身进行了分析,识别出能够反映流体沿断裂带活动的信息.流体沿断裂带向上运移时会使周围介质及其自身发生变化,如:断层附近的温度、压力异常及围岩出现的岩石矿物学异常通常与流体活动有关,流体本身的性质也因在断层中运移而发生改变.这些流体活动带来的异常及变化就是流体沿断裂带活动的有力证据.     

气体钻井中井眼温度变化及其对注气量的影响

目前关于气体钻井时所需注气量的计算方法均是将环空流体的温度取同一深度的自然地层温度来进行计算，没有考虑井眼内流体与地层进行换热的影响，这必然会带来误差。而且随着井深的增加，这种误差还会相应增大。为此，根据能量守恒原理，建立了考虑井筒流体与地层换热对井筒流体温度影响在内的数学模型，并进行了求解。然后利用求解获得的环空流体温度计算了所需注气量，并将其与按照地层未受干扰温度所得的注气量进行了对比。结果表明，按照自然地层温度所得的注气量偏小，并随着井深的加大该差值会逐渐增大。因此，在进行深井气体钻井作业时需要考虑地层与井眼流体换热的影响来计算井眼流体温度，进而确定出合理的注气量。     

流体定性温度对换热网络模拟及优化的影响

合理的定性温度能够准确表现流体的特性,在综合现有定性温度表示方法的基础上,以流体比热容的影响为例,在取不同定性温度的条件下,进行了换热网络模拟及优化计算,并对计算结果进行了分析比较。结果表明,流体的物性随温度变化越明显,定性温度选取对换热网络计算和优化的影响就越大;换热网络中流体的温度变化越剧烈,物性的变化就越大;在换热网络的优化过程中,使用不同的定性温度确定方法会影响到换热网络的结构、流体的匹配关系、换热单元数目等。     

考虑循环温度影响下注水泥流变性能计算方法

在注水泥过程中,钻井液与水泥浆在不同井深位置所受到的作用温度是不同的。在深井情况下,高温对流体流变性能的影响更加明显。通过对高温高压流体流变实验数据的分析处理,建立了通过测定2个温度下流体流变性能数据,从而计算不同温度下流体流变性能变化规律（剪切应力）的计算模型与方法,并提出了针对深井注水泥具体分段考虑温度对流变性影响计算的方法。通过对流变实验测试数据的计算误差分析,说明该计算方法的实际误差是可接受的,计算方法是可行的。      

形状记忆筛管膨胀性能测试

为了解形状记忆筛管在井下环境的膨胀性能,根据该筛管在井下的膨胀原理,研发了能够模拟井下环境的形状记忆筛管膨胀性能测试系统,进行了形状记忆筛管样机膨胀性能测试,分析了循环流体排量和温度对响应温度、膨胀速度和膨胀力的影响。研究结果表明:随着循环流体排量增大,响应温度随之升高,膨胀速度降低;当循环流体温度不低于初始响应温度时,随着循环流体温度升高,膨胀速度增大;循环流体的排量和温度对最终膨胀力的影响较小。测试结果为形状记忆筛管的设计和应用提供了依据。      

考虑地层非稳态传热的井筒流体温度预测简化模型

井筒流体温度分布是进行油气井测试分析、生产优化设计及工况分析的重要基础,然而严格的温度 预测理论模型因过于复杂且依赖于部分无法准确给定的数据而难以应用。基于前人的研究,建立了考虑 地层非稳态传热的井筒流体温度预测简化模型,该模型可避免因难以计算总传热系数而无法确定井筒流 体温度的问题。实例表明,考虑地层非稳态传热的井筒流体温度预测模型能较好地预测不同生产时间井 筒流体温度的变化以及井筒流体温度达到稳定时所需的时间。     

丙烯液相本体聚合反应体系的物性计算方法

通过再参数化PC-SAFT状态方程,建立了丙烯-氢气-聚丙烯体系各组分物性的计算方法。以文献数据为基准,利用Polym er P lus软件平台,分别得到了丙烯、氢气、聚丙烯纯组分的PC-SAFT方程的模型参数,包括链段数m、链段直径σ、能量参数ε/kB以及丙烯-氢气两组分相平衡的二元交互参数kij。结果表明,采用再参数化的PC-SAFT状态方程计算丙烯、氢气热力学性质的精度优于经典的Peng-Rob inson方程。     

深水钻井隔水管增压排量对井筒温度分布的影响

由于受深水低温特性的影响,深水钻井中,井筒流体温度分布的计算与陆地钻井中井筒流体温度分布有所不同。隔水管增压管线排量的存在使流体温度进一步降低,因此深入了解增压管线内排量对深水钻井井筒流体温度分布的影响规律十分重要。基于无隔水管增压排量下深水温度分布的计算方法,考虑突扩孔道流动的问题,结合热力学相关理论,对加隔水管增压管线排量时的深水钻井井筒流体温度分布进行了研究,建立了该情况下温度分布的预测方法,得到了井筒流体温度分布。研究结果表明:隔水管增压管线排量对深水井筒流体的温度分布影响明显,且影响区域较大;较管柱而言,增压排量对环空内井筒流体温度场分布的影响更为明显;因钻井液和流动方向的不同,较环空而言,管柱内钻井液温度受增压排量的影响更深。因此,研究深水钻井中的深水温度分布时,隔水管增压排量的影响必须加以考虑。      

Experimental study and a proposed new approach for thermodynamic modeling of wax precipitation in crude oil using a PC-SAFT model

A powerful method is necessary for thermodynamic modeling of wax phase behavior in crude oils,such as the perturbed-chain statistical associating fluid theory(PC-SAFT).In this work,a new approach based on the wax appearance temperature of crude oil was proposed to estimate PC-SAFT parameters in thermodynamic modeling of wax precipitation from crude oil.The proposed approach was verified using experimental data obtained in this work and also with those reported in the literature.In order to compare the performance of the PC-SAFT model with previous models,the wax precipitation experimental data were correlated using previous models such as the solid solution model and multi-solid phase model.The results showed that the PC-SAFT model can correlate more accurately the wax precipitation experimental data of crude oil than the previous models,with an absolute average deviation less than 0.4 %.Also,a series of dynamic experiments were carried out to determine the rheological behavior of waxy crude oil in the absence and presence of a flow improver such as ethylene–vinyl acetate copolymer.It was found that the apparent viscosity of waxy crude oil decreased with increasing shear rate.Also,the results showed that the performance of flow improver was dependent on its molecular weight.     

Fluid phase equilibrium prediction of acid gas solubility in imidazolium-based ionic liquids with the Peng-Robinson and the PC-SAFT models

In this research, the solubility of two single gases, hydrogen sulfide and carbon dioxide, in the sixteen ionic liquids ([emim][eFAP], [emim][EtSO₄], [emim][OTf], [emim][Tf₂N], [bmim][BF₄], [bmim][OTf], [bmim][PF₆], [bmim][Tf₂N], [hmim][PF₆], [hmim][Tf₂N], [omim][PF₆], [omim][Tf₂N], [HOemim][BF₄], [HOemim][OTf], [HOemim][PF₆] and [HOemim][Tf₂N]) are modeled using the Peng-Robinson and the PC-SAFT equations of state. For the ionic liquids, the pure component parameters of the PC-SAFT EoS have been obtained by the predictions of the model to both of experimental H₂S and CO₂ solubility data in ionic liquids as well as experimental liquid density data. Also, the critical properties and acentric factor of the ionic liquids were estimated using the modified Lydersen-Joback-Reid method. In the next step, the temperature-independent interaction parameters between the ionic liquids and the gases for both equations of state were calculated by fitting to the experimental VLE data and the obtained results were analyzed. In most of the studied binary systems, the percent average absolute deviation was lower than 10% that shows good agreement between the experimental and predicted values.     

Prediction of asphaltene precipitation from n-alkane diluted crude oil by using PC-SAFT equation of state

The precipitation tendency of heavy organics such as asphaltene has posed great challenges for petroleum industry, and thus study of asphaltene precipitation amount and formation conditions seems to be necessary. One of the most common approaches for prediction of asphaltene precipitation is using thermodynamic models. In this study a PC-SAFT equation of state (EOS) is used to predict asphaltene precipitation in two Iranian dead oil samples. Asphaltene content is obtained by filtration method of the oil samples diluted with specific concentrations of different normal alkanes. Also liquid-liquid equilibrium is used for characterization of oil sample into one heavy phase (asphaltene) and another light phase (saturates, aromatics, and resin). Calculations show that the developed model is highly sensitive to interaction parameter between oil fractions. Prediction results were improved due to using Chueh-Prausnitz equation. The results indicate good potential of PC-SAFT EOS in the prediction of asphaltene precipitation in crude oil samples diluted with different normal alkanes. The model error is <5% and the model precision is increased by reducing the number of normal alkane carbons.     

Thermodynamic modeling of ternary systems containing imidazolium-based ionic liquids and acid gases using SRK,Peng-Robinson,CPA and PC-SAFT equations of state

Abstract

In this study, the cubic and the associative equations of state are applied to model the VLE data of ternary systems containing ionic liquids. In the first section, the simultaneous solubility of CO₂ and H₂S in the ionic liquids [omim][Tf₂N], [omim][PF₆] and [bmim][PF₆] is modeled and the selective absorption of CO₂/H₂S is investigated at the temperatures T/K = (303.15 and 343.15) and the pressures P/MPa = (0.1 and 1). According to the obtained results, the percent deviations in pressure were varying between 6.0 and 10.8 for the SRK EoS, 6.0 and 10.6 for the PR EoS, 2.6 and 9.6 for the CPA EoS and 3.4 and 6.1 for the PC-SAFT EoS. Also, percent deviations in vapor phase composition were varying between 3.1 and 4.9 for the SRK EoS, 3.3 and 4.9 for the PR EoS, 3.1 and 7.0 for the CPA EoS and 3.8 and 4.9 for the PC-SAFT EoS. In the selectivity calculations, at high ionic liquid concentrations, the cubic models predict the selectivity drop; while the associative models present increasing trend. In the second section, the CO₂ solubility in ethanol and [emim][Tf₂N] as well as the mixture of ethanol and [emim][Tf₂N] is modeled and the experimental points were tested for thermodynamic consistency. According to the obtained results, the percent deviation in pressure of the ternary systems was 3.9 for the SRK EoS, 3.9 for the PR EoS, 3.8 and 4.0 for the CPA EoS and 3.1 and 3.2 for the PC-SAFT EoS. In the same temperature and pressure, the CO₂ solubility decrease when the concentration of ethanol increases, and the proposed models can describe this phase behavior.     

A New Investigation on Asphaltene Precipitation: Experimental and a New Thermodynamic Approach

The process of asphaltene precipitation has a substantial effect on oil production in petroleum industry. In this work, a series of experiments was carried to determine the asphaltene precipitation of crude oil during solvent titration condition with Iranian crude oil sample using experimental set up. The precipitants such as pentane, heptanes, hexane, nonane and decane with varying volumes were used. Also, a developed thermodynamic model based on micellization and PC-SAFT (perturbed chain modification Statistical Associating Fluid Theory) has been proposed to account asphaltene precipitation during solvent titration conditions and the proposed model was verified using experimental data obtained in this work and also with those reported in the literature. In the proposed micellization model the PC-SAFT EOS (cubic equations of state) is applied to predict the onset point and to perform flash calculations. In order to compare the performance of the proposed micellization model, the asphaltene precipitation experimental data were correlated using existing micellization model and the proposed micellization model. The results show that the proposed micellization model predicts more accurately the asphaltene precipitation experimental data and is in agreement with the experimental data of reported in this work and with those reported in the literature with a mean square error of 0.9%. Therefore the predictions obtained from this proposed model, resulted in a good agreement with experimental data which shows a significant improvement in comparison to the previous micellization model in the available literature.     

烯烃、二氧化碳及氢气反应体系的热力学分析

基于Benson基团贡献法,计算了环己烯、乙烯、二氧化碳及氢气参与反应中可能涉及物质的热力学数据ΔfHm0、Sm0、Cp,m。对二氧化碳存在下的环己烯、乙烯与氢气可能存在的各种反应的ΔrGm、Kp进行估算,并对这些反应的可行性和反应程度进行了分析,讨论了温度和压力对反应的影响。研究表明低温高压对体系中各反应有利,二氧化碳氢化形成一氧化碳、甲酸,羧酸氢化形成醛是热力学不利的反应,烯烃氢化形成烷烃、醛氢化成醇、烯烃与二氧化碳、一氧化碳反应形成羧酸及醛在一定温度范围内是热力学有利的反应。烯烃的结构对反应热力学也有很大影响,乙烯比环己烯更易甲酰化。     

用测井资料识别烃源岩

根据烃源岩的地质特点,提出了地层的弹性参数,铀／钍比等几个参数也可以反映地的有机碳含量问题,应用以下2种方法计算地层有机碳含量,（1）声波时差与电阻率曲线叠法,（2）根据实验结果建立的有机碳含量与地层测井响应的回归方程,2种方法的计算结果与实验结果符合较好。     

常减压装置全产品碳足迹评价研究与应用

石油化工生产过程具有投入1种原料生产多个产品的特点,碳足迹评价中以产品质量来分配共生过程的碳排放量,其结果不能体现生产过程碳排放的来源。石油化工装置能量利用状况是影响碳排放的重要因素,依据产品在生产过程中的能量变化过程进行碳足迹评价,其结果可以反映产品生产所导致碳排放的根源和本质。对某10 Mt/a常减压装置的换热网络和分馏塔进行能量核算,确定产品的能量变化过程,依据用能系统的碳排放计算碳足迹。结果显示：其减压塔顶油气碳足迹最高,达到43.748 kgCO₂/t,常一线碳足迹最低,为11.546 kgCO₂/t;由所有产品碳足迹计算的碳排放与装置碳排放吻合。因此基于能量平衡的产品碳足迹评价方法,可以按照产品在生产过程中的能量变化将装置的碳排放分配到所有产品中,产品碳足迹结果与碳排放的来源相一致。     

鄂尔多斯盆地奥陶系碳酸盐岩脉流体包裹体碳氧同位素分析

研究了鄂尔多斯盆地流体包裹体的CO₂成因及其与油气演化的关系,应用同位素分馏方程计算了奥陶系碳酸盐岩脉流体包裹体中CO₂的碳同位素值和H₂O的氧同位素值.结果表明,其碳、氧同位素值分别为-1.64‰~-11.15‰和-22.12‰~-33.06‰.该包裹体的CO₂以无机成因为主,其碳同位素组成形成于100℃~160℃的条件下,对应于油气演化的成熟-高成熟阶段.