萨北开发区北Ⅲ-5-3注入站聚合物溶液粘度的影响因素研究

研究聚合物溶液粘度的影响因素及损失规律,有利于采取有效措施降低其粘度损失,确保溶液配注质量,提高聚合物驱油效果。通过对大庆油田采油三厂北部过渡带聚合物溶液粘损调查,从剪切、水质两方面,对聚合物溶液粘度的主要影响因素进行分析,总结出注入聚合物溶液的粘度影响因素。为进一步提高注入聚合物溶液粘度,保证聚合物驱油效果提供了理论依据。     

动态成型注塑螺杆熔体输送能力的研究

根据动态注射成型时螺杆的工作特点，采用自行修正的Tanner本构方程研究了聚合物熔体在螺槽中的等温流动。同时，近似地给出了振动力场下注塑螺杆熔体输送能力的表达式，理论分析了振动参数对沿程压力降及动态成型熔体输送能力的影响。结果表明，振动力场使塑化过程中聚合物的粘度降低，流动阻力减小。沿螺槽方向的平均压力降减小，在保持成型条件不变的情况下，施加振动可以提高熔体输送能力。     

工业烧嘴冷却水管路阻力损失的计算

分析了影响工业烧嘴冷却水管道沿程阻力损失的因素,明确了沿程阻力系数是主导因素,计算了工业烧嘴冷却水管路阻力损失。检验表明,计算值与实测数据符合较好,说明计算方法可用于阻力损失的实际计算,指出螺旋管的盘绕方式和几何因素对流动阻力的影响不可低估。研究结果可为烧嘴的设计和烧嘴冷却水泵选型等提供科学依据。     

七中区二元复合驱高压止回阀粘损测试与改造

在克拉玛依油田七中区二元复合驱工业性试验中,取样化验得出了防回流高压止回阀对聚合物液的粘度损失数据,实测得到止回弹簧自由伸长、实际止回伸长、弹性系数、止回锥形阀体开启力、弹簧最大压程等基本参数。根据液流阻力计算出锥形阀工作时的开度,以及液流阻力产生的能耗。缩短弹簧自由伸长可降低锥形阀体的水头损失及粘损,兼顾锥形阀体在回流时可靠关闭,将环形通道的自由宽度设计为3mm。经现场验证改进后的止回阀工作可靠、粘损下降,获得了满意的效果。     

油品粘度对输油管道弯管结构的影响规律分析

对于长距离输送管道而言,为了提高管道的输送效率,降低输送成本,如何有效地降低沿程损失便成为首要解决的问题。具有较高粘度的油品会大大增加输送过程中的沿程摩阻损失,为了更好地分析油品粘度对管道的影响,通过建立输油管道弯管结构的有限元力学模型,针对油品流经管道弯管时,油品粘度对管道温度场与应力场的影响规律进行分析。研究结果表明,油品粘度在增加管道沿程损失与局部摩阻损失的同时,也给弯管处温度场与应力场造成极大的影响,并且对管道温度场与应力场的作用规律不尽相同,这对输油管道弯管结构的安全性产生较大的危害。通过研究分析了油品粘度对管道的影响规律,为油品的降粘输送提供了理论指导依据。     

新的管件当量长度计算图

在管路的水力计算中,我们要考虑两种阻力损失:(1)沿程阻力(由导管本身产生的阻力);(2)局部阻力(由于管路截面变化、方向改变、及管路上各种管件所产生的阻力)。在现代化的化学、石油等工厂里都有着复杂的工艺管线,因此管路设计时,计算量很大。本文主要介绍一张自己绘制的局部阻力当量长度计算图,用它可以简化计算。沿程阻力的计算一般采用达西公式:     

玻璃钢管道沿程水头损失实验研究

针对管径小于100 mm的玻璃钢管道沿程水头损失计算问题,建立了一套测定沿程阻力的实验装置,测量得到不同流量下4种不同管径玻璃钢管道的沿程水头损失。选用伍德公式、海曾-威廉公式等一系列经验公式分别对实验管道进行沿程水头损失拟合,并与实测数据进行比较。结果显示:伍德公式的拟合结果与玻璃钢管道的实测沿程阻力结果最为接近,同时对玻璃钢管道的海曾-威廉系数进行了修正。     

流动改进剂对含水原油沿程阻力的影响

含水原油在长输管道中输送要克服很大的沿程阻力,为了提高其管道输送效率,开展了降低含水原油沿程阻力试验研究,主要方法是在管道中加入适量浓度的流动改进剂改善含水原油在管道中的流动性能,通过实验研究掌握加入适量浓度流动改进剂后含水原油沿程阻力规律,绘制出管道压降与流量关系曲线图,证明流动改进剂可以显著降低含水原油的沿程阻力,对于改善其流动性,降低含水原油的集输成本和能耗,具有现实意义。     

污水配制聚合物溶液影响因素及增粘效果分析

针对大庆油田污水配制聚合物溶液存在严重粘度损失的问题,研究了污水中阴阳离子对聚合物溶液粘度的影响并提出改善措施。研究表明:对聚合物溶液粘度影响较大的是阳离子,其顺序是:Fe~(2+)Fe3~+Mg~(2+)(Ca~(2+))Na~+(K~+)。配置要求是Na~+、K~+含量3 000 mg·L-1,最好控制在1 000 mg·L-1以下;Ca~(2+)的含量200 mg·L-1,Mg~(2+)含量100 mg·L-1。Fe~(2+)、Fe~(3+)的影响严重,需严格控制含量;而阴离子对聚合物溶液粘度的影响可以忽略不计;该镁离子为该区块影响聚合物溶液粘度的主要因素。利用腐植酸钠吸附法去除溶液中的钙镁离子,经离子吸附处理后溶液增粘14.2 m Pa·s。腐殖酸钠混合液用量为8.0 m L时对钙离子的吸附率达到77.50%,腐植酸钠混合液用量为6.0 m L时对镁离子的吸附率达到83.60%,说明可以用腐殖酸钠对钙、镁离子进行处理,且增粘效果良好。     

同心分注技术在港西油田注聚井的应用

注聚同心分注技术可有效地避免聚合物溶液粘度降低,提高聚合物驱油效果,同时解决多年来注聚井难以实施多层段分注的难题。该技术采用环型降压槽设计,使聚合物溶液能达到预定的流量和压差,在低流速状态下流经配水器,避免传统配水器在节流时对聚合物溶液产生的剪切降解,有效地提高聚合物的驱油效果。     

水平管内水环输送模拟稠油减阻特性

基于自主设计加工并搭建的水环输送稠油减阻模拟管路系统,采用500^#白油模拟稠油,试验研究了稠油在水环作用下的水平管流阻力特性,分析了油相表观流速（0.3～1.0m/s）、水相表观流速（0.11～0.72m/s）及入口含水率（0.13～0.49）对水润滑管流流型特征及减阻效果的影响。结果表明：环状水膜可有效隔离并润滑油壁界面,油-水两相流流型总体上呈稳定的偏心环状流结构;水环输送可大幅降低管道输送过程中的压降,其压降值仅为相同油流量下纯油输送压降的1/55～1/27;当入口含水率为0.13～0.27时,水环输送的效能显著,输油效率均高于40;油相表观流速和入口含水率的增加会增大单位管长压降,降低水环输送的减阻效果和输油效能。     

Study on properties of hydrophobic associating polymer as drag reduction agent for fracturing fluid

In the paper, the hydrophobic associating polymer ACS-210 was prepared by solution polymerization of acrylamide, acrylic acid, salt-resisting monomer and hydrophobic monomer. Chemical structure and properties of the polymer was characterized by FTIR, TGA and XRD. The rheological property of ACS-210 solution was investigated by rheometer. The frictional resistance of the ACS-210 solutions at different application condition was examined using friction testing system. Results showed that the thermal stability of polymer ACS-210 increases and crystallinity of ACS-210 declines after incorporating of hydrophobic monomer. The viscosity of ACS-210 solution of different concentration decreased with prolonging the shearing time and the retention rate of viscosity is relatively high after long shearing time. The relation curve between the viscosity of polymer solution and shear rate followed the power law model. When the concentration of ACS-210 aqueous solution was less than the critical associating concentrations, storage modulus G’ is less than loss modulus G”, the association was weaker between the molecular chains, and the effective spatial structure did not form. After increasing the concentration of the polymer solution, G’ is more than G”, the degree of association of polymer is stronger. The synthesized polymer has favorable drag reduction effect. The molecular weight is not the only factor to determine drag reduction efficiency. The hydrophobic association can also improve the drag reduction efficiency.     

Anomalous friction in slurry flows

Experiments conducted with water slurries of 1 mm particles of specific gravity 1.59 in a laboratory pipeline 0.105 m in diameter have provided evidence of a change in the friction mechanism at velocities above 3 m/s. These flows were stratified and at low velocities the frictional pressure gradients were in satisfactory agreement with the predictions of the conventional two‐layer model. However at higher velocities the friction is substantially lower than predicted. Measurements of concentration and velocity distributions within the pipe show that no major change in flow regime occurs concurrently with the change in the friction mechanism. It appears that the effect is due to a change in the nature of the particle‐wall interaction, of a type which suggests that an inward‐acting force affects the particles adjacent to the wall.     

DRAG REDUCTION IN ARTIFICIALLY ROUGHENED PIPES

The influence of an extremely rough surface on the drag reducing properties of polymer solutions is studied by pressure drop measurements in a rough pipe. It is shown that the onset of drag reduction for a homogeneous dilute polymer solution in a rough pipe occurs at the same wall shear stress as in a smooth pipe of the same diameter. In addition, the maximum drag reduction is almost the same in both types of pipes. Similar results are found for so-called heterogeneous drag reduction obtained by injecting a concentrated polymer solution in the centre of the pipe. The injected polymer solution, which is convected along the centre of the pipe as an elastic thread, disintegrates into fine polymer threads in the rough pipe leading to an increased drag reduction. In this case the injection of the same amount of polymer in the form of a concentrated solution is more effective than a homogeneous polymer solution.     

Mechanical Energy Losses in Horizontal,Inclined and Vertical Intermittent Two-Phase Flows with Drag-Reducing Polymer

Mechanical energy loss is usually considered to be generated from frictional pressure drop in pipe flow. An analytical equation was derived from hydrodynamic model to estimate the mechanical energy loss in intermittent two-phase flow. This equation indicates that only part of energy loss is generated from frictional pressure drop in inclined and vertical intermittent flows. Experiments were conducted in a gas–liquid pipeline to investigate the different effects of drag-reducing polymer (DRP) on the mechanical energy losses of turbulent intermittent flows in pipes. The inside diameter of the pipeline is 0.04 m. Whether or not DRP is used, the results show that the mechanical energy loss is highest in the vertical case and is lowest in the horizontal case among horizontal, inclined, and vertical intermittent flows. The energy loss reduction induced by DRP in horizontal intermittent flow is greater than the one in either vertical or inclined intermittent flow.     

Study of oil soluble polymers as drag reducers

This investigation was undertaken to find the most effective material which would reduce the friction coefficient in turbulent flow when added in small quantities to oil pipelines. For this purpose, a series of oil-soluble polymers, namely homopolymers and copolymers of alkyl methacrylates, alkyl acrylates, and alkyl styrenes were synthesized. Emulsion polymerization techniques were used. Commercially available alkyl methacrylate and alkyl acrylate monomers were used in the synthesis. Monomeric alkyl styrenes were synthesized and structures established prior to polymerization. Intrinsic viscosities were measured and viscosity average molecular weights were calculated for several of the homopolymers synthesized in this study. Reduction of factional drag and resistance to shear degradation were measured by pumping a solution of the polymer in a hydrocarbon solvent through a pipe and recording the pressure drop across the pipe. Drag-reducing properties of several of the polymers were correlated in terms of their viscosity average molecular weights. Drag reduction of poly (isodecyl methacrylate) was studied in various hydrocarbon solvents. Drag-reducing behavior of polymers prepared in this study exhibited a strong dependence on molecular weight; increasing the molecular weight increased the drag reduction for a given polymer concentration and pipe size. Several of these polymers were found to be superior to commercially available polyisobutylene as drag reducers, especially in terms of shear stability.     

Experimental research on drag reduction by polymer additives in a turbulent pipe flow

In order to investigate the effects of injection position on drag reduction as well as further the effects of polymer additives on turbulent structures, LDA measurements of turbulent pipe flows were conducted. The results show that the amount of drag reduction grows with the increase of the Reynolds number, and injecting the polymer at the centre of pipe is more effective than at the wall. Due to the addition of polymer solution, the axial, radial r.m.s. velocity fluctuations and Reynolds stress decrease over the entire pipe cross‐section, the time auto‐correlation coefficients of axial and radial velocity fluctuation at the centre of pipe decay more slowly, the number of spectrum peaks is decreased, and the peak shifts towards lower wave numbers. The results also reveal that, due to the addition of polymer solution, the large‐scale vortices are enhanced and small‐scale vortices are suppressed.     

油水混合物在水平管中的二相流动特性研究

对内径40mm的钢管和有机玻璃管内油水二相水平流动时的流型、摩擦压降特性进行了详细的实验研究,结果表明:油包水向水包油的转变发生在含水体积分数约0. 4时。随含水体积分数的增大,油水二相流的摩擦压降先是急剧减小,其后在含水体积分数大于0. 4时压降变化趋于平缓。油水二相流的摩擦压降受含水体积分数、管壁润湿特性、管壁粗糙度以及混合物流速的影响,当二相流体处于水包油状态时,钢管内的摩擦压降比有机玻璃管内的大;而当处于油包水时,有机玻璃管内的摩擦压降则比钢管内的摩擦压降大。     

Frictional properties of polyolefins treated with fluoroelastomer processing aids

A friction measurement system was designed that made possible the measurement of the friction coefficient between a polymer melt and a metal die wall. The shear stresses developed in the capillary rheometer and the friction coefficient measured in the friction measurement system were compared in an attempt to understand the mechanism of fluoroelastomer processing aids (FPA) in the extrusions of polypropylene (PP) and linear low-density polyethylene (LLDPE). The apparent viscosity drops of LLDPE treated with FPA were larger than those of PP treated with FPA. The friction coefficient drops of LLDPE treated with FPA were also larger than those of PP treated with FPA. High viscosity FPA showed a moderate friction coefficient drop in the actual extrusion of PP even though it showed only a poor effect in the capillary rheometer. The frictional forces were calculated from the friction coefficient measurement made during extrusions of FPA-treated and untreated samples. © 1995 John Wiley & Sons, Inc.     

螺旋槽干气密封端面间气膜特性

螺旋槽干气密封是一种新型的非接触式机械密封,它具有介质泄漏量少、端面磨损小、能耗低、运行寿命长和可靠性高等优点.采用有限元法对螺旋槽干气密封端面间气体的流动过程进行了数值模拟研究,得到了端面间气膜的压力分布规律并对主要的密封性能参数——开启力、端面摩擦力、摩擦功耗、轴向刚度以及泄漏量进行了计算,最后,探讨了操作参数和端面槽形几何参数对密封性能的影响.研究结果为螺旋槽干气密封的设计提供了有益的参考.