欢喜岭含水稠油流变特性实验研究

因稠油乳状液在生产和运输过程中带来的各种经济损失,所以其被称为石油行业内最为棘手的问题之一。采用RV2旋转流变仪对不同含水率下欢喜岭稠油表观粘度和流变特性进行测定。研究发现,影响稠油乳状液流变特性的因素为:温度、剪切速率和含水率;50℃为稠油乳状液的牛顿流体转化温度点;含水40%时乳状液发生转相,由油包水型乳状液转变为水包油型乳状液。稠油流变性的研究和牛顿流体转化温度点、转相点的测定对稠油管道输送、设计和改造有着重要意义。     

RHEOLOGICAL PROPERTIES AND FLOW OF CONCENTRATED DISPERSE MEDIA. II - STEADY AND UNSTEADY FLOW ANALYSIS OF HEAVY CRUDE OIL EMULSIONS

Experimental study of steady flows of heavy crude oil emulsions in rectilinear ducts provides evidence of a non newtonian behaviour in good agreement with viscometric rheological data. Superimposing an unsteady flow on the mean one, the mean flow rate is shown to be strongly increased under conditions depending on the frequency and the values of the mean and oscillatory components of the pressure gradient. The mean features of such an enhancement are then interpreted in relation to the rheological behaviour of the fluid.     

降凝降黏剂在原油开采集输中的应用

降凝降黏剂已成为钻高难度的高温深井、大斜度定向井、水平井和各种复杂地层的重要手段,并且还可广泛地用作解卡液、射孔完井液、修井液和取心液等。由于稠油的黏度以及凝点低,防止在开采过程中出现困难,降凝降黏剂的应用需要进行一定的关注,解决其发展困难。     

塔河超稠油掺苯乙烯焦油降黏实验及黏度预测模型

针对塔河油田12区超稠油的性质,进行了超稠油掺苯乙烯焦油降黏实验及黏度预测模型的研究。采用苯乙烯焦油和柴油对超稠油进行不同掺稀比的降黏实验,用非线性宾汉模型进行流变数据拟合,并将实验测得的混合油黏度与预测模型进行匹配。结果表明：超稠油掺混20%苯乙烯焦油的降黏效果与超稠油掺混10%柴油的降黏效果相同,降黏率大于97%,掺稀比越大、温度越高,混合油黏度越低。混合油的流变模型符合非线性宾汉模型,呈现出一定的剪切稀释性。当超稠油与苯乙烯焦油的黏度比低于1.76×10⁴时,混合油黏度可采用Cragoe修正模型和双对数修正模型Ⅱ进行计算,双对数修正模型Ⅱ对苯乙烯焦油与超稠油混合油的黏度预测效果最好,平均相对偏差为9.4%。     

RHEOLOGICAL PROPERTIES AND FLOW OF CONCENTRATED DISPERSE MEDIA. II - STEADY AND UNSTEADY FLOW ANALYSIS OF HEAVY CRUDE OIL EMULSIONS

Experimental study of steady flows of heavy crude oil emulsions in rectilinear ducts provides evidence of a non newtonian behaviour in good agreement with viscometric rheological data. Superimposing an unsteady flow on the mean one, the mean flow rate is shown to be strongly increased under conditions depending on the frequency and the values of the mean and oscillatory components of the pressure gradient. The mean features of such an enhancement are then interpreted in relation to the rheological behaviour of the fluid.     

Synthesis and mechanism analysis of a new oil soluble viscosity reducer for flow improvement of Chenping heavy oil

Oil soluble viscosity reducers have gradually attracted the attention of petrochemical research due to their cleanliness and high efficiency. Considering the high viscosity and non-Newtonian fluid properties of Chenping heavy oil found in China, a series of new oil soluble viscosity reducers with different proportions and molecular weights were prepared by free radical polymerization using octadecyl acrylate, 2-allylphenol and N-methylolacrylamide as monomers. The viscosity reducer was applied t...     

Kinetic studies on extra heavy crude oil upgrading using nanocatalysts by applying CFD techniques

Regarding the growth of global energy consumption and the paucity of light crude oil,extracting and using heavy and extra heavy crude oil has received much more attention,but the application of this kind ofoil is complicated due to its very high molecular weight.High viscosity and low flowability complicate the transportation of heavy and extra heavy crude oil.Accordingly,it is essential to reduce the viscosity of heavy and extra heavy crude oil through in-situ operations or immediate actions after extraction to reduce costs.Numerical simulations are influential methods,because they reduce calculation time and costs.In this study,the cracking of extra heavy crude oil using computational fluid dynamics is simulated,and a unique kinetic model is proposed based on experimental procedures to predict the behavior of extra heavy crude oil cracking reaction.Moreover,the hydrodynamics and heat transfer of the system and influence of nanocatalysts and temperature on the upgrading of crude oil are studied.The geometry of a reactor is produced using commercial software,and some experiments are performed to examine the validity and accuracy of the numerical results.The findings reveal that there is a good agreement between the numerical and experimental results.Furthermore,to investigate the main factors affecting the process,sensitivity analysis is adopted.Results show that type of catalyst and concentration of catalyst are the parameters that influence the viscosity reduction of extra heavy crude oil the most.The findings further revealed that when using a 25 nm SiO2 nanocatalyst,a maximum viscosity reduction of 98.67％ is observed at 623 K.Also,a catalyst concentration of 2.28wt％ is best for upgrading extra heavy crude oil.The results obtained through sensitivity analysis,simulation model,and experiments represent effectual information for the design and development of high performance upgrading processes for energy applications.     

稠油油藏多轮次吞吐中后期改善开发效果研究

针对稠油多轮次吞吐中后期油藏渗流能力差、剩余原油黏度高、含水高的特点,研制出新型高效稠油分散降黏体系FSJN。考察了体系的溶解沥青能力、耐温性、降黏率。稠油分散降黏体系能够溶解分散沥青,可耐温160℃。50℃稠油分散降黏体系用量0．6％可将原油黏度降低至300mPa·s以下。60℃、0．6％稠油分散降黏体系可提高纯热水...     

稠油注蒸汽层内化学生热温度场计算

稠油吞吐井注汽过程中,由于沿程热损失,到达油层深部的蒸汽温度较低,不能有效提高远井带油层温度,导致单井控制范围有限,因而采用层内化学生热提温技术,将生热剂段塞注入设计的油层区域,依靠生热剂反应放出大量热,提高油层深部地层温度。针对地层物理模型,根据单元体平衡法,结合傅里叶定律、牛顿公式和反应动力学方程,建立了层内传热数学模型,并对一口井进行了实例计算和分析。结果表明,采用化学生热技术,能够提高油层温度40℃左右,加热了蒸汽难以提温的远井带,改善原油流变性,促进原油流向井底,提高了单井产量。     

胶凝含蜡原油的连续剪切实验研究

胶凝含蜡原油由于其蜡晶的三维网状空间结构,具有复杂的流变性。胶凝原油的流变性质一直是研究的重点和热点。很多学者对胶凝原油的性质做了详细而又深入的研究,但这些研究一般集中在恒定剪切速率上,对胶凝原油的连续剪切的研究较少。通过控制不同的降温速率和胶凝温度,来研究胶凝原油连续剪切的变化规律。实验结果表明,当降温速率越大时,初始的粘度越小,但剪切一段时间后,不同降温速率下的粘度无多大差别;当胶凝温度越低是,其初始的结构强度越大,并且在结构破坏以后,在同一剪切速率下,其粘度也越大,但不同温度下的差距在减小;当从高到低的剪切情况下,其粘度随着剪切速率的减小,呈增大的趋势,并且这趋势越来越明显,相对于从低到高的剪切情况下,在同一剪切速率下,从低到高情况下的粘度比从高到低的粘度要大。     

Effects of asphaltene content on the heavy oil viscosity at different temperatures

Asphaltene content plays an important role in determining the high viscosity of heavy oil. This paper presents an experimental and theoretical study of the specific effects of asphaltene content on the heavy oil viscosity at different temperatures. In the experiment, a deasphalted heavy oil is obtained by using a standard ASTM method to precipitate asphaltenes from a crude heavy oil. Then eleven reconstituted heavy oil samples are prepared by adding the precipitated asphaltenes into the deasphalted heavy oil at a different asphaltene content each time. The viscosities of such reconstituted heavy oil samples with different asphaltene contents are measured at six different constant temperatures by using a cone-plate viscometer. Theoretically, two viscosity models for a colloidal dispersion system are applied to find the best fit to the experimental data by using non-linear regression. The following four important parameters are thus determined to characterize the reconstituted heavy oil samples: the solvation constant, shape factor, intrinsic viscosity, and maximum packing volume fraction. The detailed non-linear regression results show that the state of asphaltene particles in the heavy oil changes with the asphaltene content and temperature and that this state change strongly affects the heavy oil viscosity.     

Heavy crude oil viscosity reduction and rheology for pipeline transportation

Different methods of reducing the viscosity of heavy crude oil to enhance the flow properties were investigated. Experimental measurements were conducted using RheoStress RS100 from Haake. Several factors such as shear rate, temperature and light oil concentration on the viscosity behavior have been studied. This study shows that the blending of the heavy crude oil with a limited amount of lighter crude oil provided better performance than the other alternatives. Experimental measurements in terms of shear stress τ-shear rate and yield stress τ₀ were conducted on the mixture of heavy crude oil-light crude oil (O-light). The results showed a significant viscosity reduction of 375 mPa s at a room temperature of 25 °C. This study shows that the heavy crude oil required a yield stress of 0.7 Pa, whereas no yield stress was reported for the heavy crude oil-light crude oil mixture.     

High-pressure viscosity of used motor oil/vacuum residue blends

The overall objective of this work was to characterize and model the temperature-pressure-viscosity relationship for used motor oil, and its blends with heavy petroleum residue, in a wide range of pressure and temperature. With this aim, used motor oil, and a vacuum residue commonly used as bituminous base were used as components of the blends. Blends of used motor oil and vacuum residue were prepared by mixing both components in a batch tank with a four-blade impeller. Subsequently, the mixtures were stored at room temperature. The rheological study was performed using a controlled stress rheometer, using both a conventional coaxial cylinder geometry, and a coaxial cylinder-pressure cell. From the experimental results obtained it is apparent that whilst the used motor oil behaves as a Newtonian liquid, the blends behave as non-Newtonian fluids, showing a shear-thinning behaviour in most of the shear rate range studied, at atmospheric pressure, in a temperature range comprised between 0 and 60 °C. The viscous flow curves results obtained at different differential pressures prove that the influence of time-dependent phenomena on viscosity is not significant in most of the shear rate range studied (between 1 and 100 s⁻¹). Pressure-temperature-viscosity relationship modelling, at constant shear rate, can be performed from pressure sweep data at constant temperature, temperature sweep data at constant pressure, or pressure-temperature sweep data. In this sense, the FMT predicts the above-mentioned relationship fairly well.     

高效活性解堵工艺在解除洗井污染上的应用

文明寨油田部分生产油井存在结蜡、油稠、井温低的现象,在保持正常生产时不可避免的要采取洗井等措施,当洗井液与地层流体、岩石不配伍时,会对油气层造成损害或堵塞,严重时会造成水锁损害,短期或长期影响油井产量。文章究污染油层的机理出发,结合单井生产实际,采用高效活性解堵工艺,成功解除洗井替油过程中造成的油层污染问题。     

锡14块特超稠油流变性实验研究

稠油流变性特征对稠油开采、数值模拟、集输工艺等均是有重要的参考作用,用旋转粘度法研究了中原油田锡14块原油的粘-温特性和流变特性。结果表明：温度越低,该区块稠油粘度对温度变化越敏感,原油的粘-温拐点为70℃,油藏温度下屈服值达到61.3 Pa,原油的牛顿流体转化温度在85～90℃以上;含乳化水30%左右时,在50～90℃温度范围内乳化水对原油粘度有较大影响。     

安塞油田化学清防蜡工艺效果分析

含蜡原油开采过程中,油井普遍存在结蜡现象。行之有效的清防蜡工艺是保障油井稳产的重要因素,化学清防蜡工艺应用效果受沉没度、产液量及含水率等的影响,在油井复杂条件下,其现场应用效果难以评价。为研究清防蜡工艺的应用效果,本文基于清防蜡工艺原理,以安塞油田清防蜡工艺应用前后的高含蜡原油和沉积物为研究对象,分析了原油族组成、蜡组成、蜡含量、析蜡点、黏度和溶蜡速率;通过比较确定了4个评价指标,引入多目标评价方法,建立了清防蜡工艺效果评价体系。研究表明清防蜡工艺应用后原油黏度降低;蜡的碳数C₁₆~C₃₀的百分含量降低,C₃₀以上的百分含量升高;原油平均蜡含量变化率为22.99%;原油平均析蜡点变化率为2.86%;各清防蜡剂溶蜡速率均大于0.0160g/min;CQ-1工艺和CQ-2工艺的综合得分较高,现场应用效果良好。计算结果与安塞油田应用化学清防蜡工艺的方向一致,具有较强的参考性。     

庆45区块稠油蒸气驱生产井闪蒸预测分析

在大庆油田庆45区块稠油蒸气驱生产过程中,地层的非均质性导致局部受效层温度过高,引起井底闪蒸。根据传热学和计算流体动力学理论,建立井底温度计算模型,提出闪蒸预测方法,将计算的井底温度、压力与水饱和蒸汽临界温度-压力曲线相结合,依据井底温度和压力在临界曲线上的相对位置判断井底闪蒸情况。以庆45-22-K281井为例,进行现场测试和井底闪蒸预测。预测结果与实测结果表明,闪蒸预测方法有效,为稠油蒸气驱生产井的闪蒸防治提供依据。     

A Simple Model for Predicting the Two-Phase Heavy Crude Oil Horizontal Flow with Low Gas Fraction

A two-phase heavy crude oil flow with low gas fraction is common in the oil transportation process. However, most of the studies of a gas–liquid flow are based on low viscosity fluid, such as water and light oil; as a result, the results cannot be introduced successfully into the mixture flow of gas and heavy crude oil. In this work, a two-phase flow of gas and heavy crude oil, which originated from the Bo-hai oilfield in China, was investigated in a horizontal pipe with 47-mm inner diameter. Data were acquired for the oil flow rate ranging from 2 m³/h to 10 m³/h, the input gas volume fraction ranging from 0.01 to 0.15, and the viscosity of crude oil ranging from 2.41 Pa·s to 0.34 Pa · s. Based on the drift-flux model, a new simplified correlation was developed to predict the void fraction and the pressure gradient. A comparison between the predicted and measured data demonstrates a reasonable agreement, and the correlation might be helpful for practical application in industry, especially in initially estimating the flow characteristic parameters.     

稠油冷采技术现场应用及研究

针对辽河油田曙光稠油蒸汽吞吐区块多数进人高轮次阶段,地层能量低等矛盾,研制一种提高地层能量、稀化降低原油粘度、提高回采速度和回采水率,减少对地层伤害的一种新技术方法.现场实施43井次,成功率为100％,开采效果显著.     

井下串联抽稠油泵研究

为解决稠油粘度高、在井筒中流动阻力大的问题,设计了井下串联抽稠油泵.阐述了泵的结构和工作原理,对弹簧、悬点载荷、泵排量等工作参数展开分析,并进行了可行性论证.该泵在上冲程时从油管掺入降粘液,并吸入地层产出液;在下冲程时将二者混合并通过油套环空举升至地面.该泵实现了柱塞下掺液,避免了砂磨柱塞现象以及泵上掺液不能降低原油进泵粘度的问题.该泵原理可行,工艺容易实现,成本低,可广泛应用于稠油举升.