基于V型内锥与电导环的油水两相流参数测量

油水两相流在石油工业过程中十分常见,对其流动过程参数(如流量与含率)的准确测量一直受其流态的复杂性限制而成为科学研究与工业应用中亟待解决的重要课题。差压法是常用的流量测量手段,作为差压式流量计的一种,V型内锥式流量计结合两相流动模型可实现两相流流量的测量。电学法通过测量两相混合物电学性质(如电导率与介电常数)的变化实现分相含率的测量。本文采用等效直径比0.65的V型内锥式流量计结合环形电导式传感器阵列实现50mm内径水平管道中油水两相流总流量、含率与分相流速的测量,针对油水两相流特性修正Chisholm分相流差压测量关系式实现油水两相流质量流量的测量,并利用环形电导式传感器阵列实现含水率与质量含油率的测量。实验结果表明,油水两相流含水率测量的平均相对误差为8.1%,质量含油率的平均相对误差为13.7%,基于修正关系式与含水率、质量含油率测量结果的油水质量流量测量平均相对误差为4.4%,油相与水相表观流速的平均相对误差分别为3.2%与15.7%。本工作为进一步提高油水两相流过程参数的测量精度打下基础。     

超声多普勒谱修正的油水两相流流速测量

针对水平管道油水两相流流速的无扰动测量问题,提出一种基于超声/电学双模态传感器的流速测量方法。测量系统由连续波超声多普勒传感器和基于电容与电导的电学传感器构成,分别用于获取两相流流速和分相含率。由于连续波多普勒的测量区域集中于管道中心,受流速剖面、含率分布影响,所测得流速并非流体的总表观流速。在假设含率分布满足高斯分布的前提下,建立相含率加权的多普勒能量谱模型,将含率分布的影响因素引入总表观流速的测量,并建立总表管流速和分相表观流速的计算模型。在试验基础上,分别确定水连续和油连续时总表观流速计算模型的参数。试验表明,通过模型计算出的表观流速与实际测量的流速能够较好吻合,总表观流速的相对误差小于6.32%,分相表观流速的方均根误差小于5.64%。     

三相流分相浓度测量平台的标定试验

根据多相流流动特性对固相质量流量及流速之间的依赖关系,通过在以气力输送系统为基础的煤粉/生物质/空气三相流分相浓度测量系统实验平台上,对固相质量流量及风速分别进行了标定试验.结合标定结果将固体颗粒质量流量转换成所需的固相体积浓度,最终达到测量系统的测试要求.     

基于BP神经网络的多相流计量方法的研究

针对原油中油、气、水多相流复杂的流动情况,利用气液分离器、水分分析仪、密度计和孔板流量计组合法的测量系统,提出了一种基于BP神经网络对传统密度法测量原理进行误差修正的多相流计量方法.利用MATLAB7.1对建立的BP神经网络进行训练和仿真,实验结果表明此方法用于多相流相分率和总流速的测量,误差范围均在±5%之内.     

一种石油生产永置式地面井口持水率动静态测量装置研究

为满足采油地面井口多相流持水率测量的实际要求,本文结合电导动态测量与筒状电容静态测量技术,研制了一种永 置式石油生产地面井口多相流持水率动静态测量装置(PDSWHMD_SM)。 具体地,文中采用有限元方法(FEM)构建了电导-电 容一体式传感器(CCIS)数值模型,在此基础上对 CCIS 管道内流体处于流动及静止状态下分相介质的分布特性、CCIS 结构参 数、CCIS 电学分布特性、不同多相流工况下的响应特性等进行了深入研究,最终确定了 CCIS 最优结构参数:He = 90 mm、ID = 30 mm、Ihe = 3 mm、Hc = 375 mm、IR1 = 26 mm、Tc = 1 mm、Hm = 56 mm,证明了其测量误差在 5% 以内。 另外,本文以总流量 5~ 70 m 3 / d,持水率 50% ~ 90% 等多相流工况为例进行了实验研究,实验结果表明:研制的装置 PDSWHMD_SM 持水率测量误差 同样在 5% 以内。 仿真和实验均证明了 PDSWHMD_SM 具有良好的持水率测量性能。     

油气水多相流在线测量技术的研究和现场应用

介绍了一种新型的油气水多相流在线测量技术,它综合利用多相流流型调整、互相关流量测量、双能伽马相分率测量、多相流模拟计算、计算机控制和通讯技术等多种现代检测和控制技术,以进行多相流在线检测;在流型适应性、测量范围和测量精度等方面的性能有重大改进;利用该技术研制的在线测量装置已通过了国内外权威机构在实验室和工业现场的测试和检定,主要性能指标均达到或超过了国外同类产品的水平,且已在油田现场应用多台.     

石油生产光纤-电导组合探针阵列多分相测井仪研究

为解决石油生产多分相测量问题,基于课题组研制的创新型光纤-电导组合探针设计研制一种用于石油生产多参数测量的高精度、高灵敏度探测仪器。采用ZEMAX光线追迹方法和FEM数值分析方法对光纤-电导组合探针阵列多分相测井仪电场分布、响应特性进行了理论分析,且验证了其在流量为5、10、20、30 m~3/d,持气率为10%、20%、30%、40%,持水率为90%、80%、70%、60%等工况下良好的测量效果。为进一步证明其优良性能,以液相流量30 m~3/d,液相持水率25%、45%、65%及85%,气流量6、12、24 m~3/d等多相流工况为例进行动态实验分析,其持气率测量误差在5%以内,持水率误差在10%以内。实际动态实验与仿真模拟结果保持相同。充分表明光纤-电导组合探针阵列多分相测井仪的良好的性能。     

新型近红外矩形差压流量计的测量模型研究

针对目前气液两相流不分离测量的难点,设计了一种基于近红外光谱技术与矩形差压流量计相结合的新型气液两相流检测装置。利用CFD流体仿真软件对影响流量计性能的结构参数进行了仿真及优化,在单相流动和气液两相动态实验的基础上,建立了相含率测量模型,修正后液相含率测量误差低于3.5%。在液相流量大于2m~3/h时,对分相流模型进行修正,得到的总流量测量误差低于4.5%。建立了两相差压与Fr_g、Frl的关系,结合相含率测量模型得到总流量测量模型,其中弹状流总流量误差低于6.5%,泡状流总流量误差低于1.5%。实验结果表明该装置用于气液两相流不分离测量的可行性,对工业领域的生产具有重要参考意义。     

油田多相流计量方法研究与探讨

分析了多相流分离计量和在线计量方法,总结了多相流计量的核心技术和研究进展,分析了弯管流量计测量油水和气水两相流实验数据,结果表明弯管测量油水两相流准确性较好,测量气水两相流误差较大.探讨了弯管流量计与密度计或与其它流量计配合的测量方案.     

气-液两相流空隙率的测量方法

两相流或多相流参数的测量在各种生产过程和能源系统中愈来愈引起人们的重视。例如,在工业系统和实验室研究中,有时需对下列对象进行测量:油田开采中油一气流量,悬浮液管道,物料的气体输送,流化床,化学反应器,脱盐装置,地热能站,核反应器等。这些测量都涉及到了多相流问题。毫无疑问,多相流参数的测量在各个领域的应用都是很重要的。在与核反应有关的研究中,对多相流参数检测技术的发展起了相当的推动作用。这里不仅仅是为了获取稳态操作下的设计信息,同时也是为了在过渡状态和事     

Three-way PLS regression and dual energy gamma densitometry for prediction of total volume fractions and enhanced flow regime identification in multiphase flow

Dual energy gamma densitometry and 3-way partial least squares regression were applied to quantify the total volume fractions and improve flow regime identification in multiphase flow. Multiphase flow experiments were carried out with formation water, crude oil and gas from different North Sea gas fields in Statoil׳s High Pressure Multiphase Flow Loop in Porsgrunn, Norway. Four different flow regimes were investigated (stratified wavy, slug, dispersed and annular). A traversable dual energy gamma densitometer was used to measure the fluid densities in the pipe. Partial least squares regression was previously applied to identify multiphase flow regimes and quantify volume fractions of gas, oil and water. That study showed promising results for flow regime identification but the predictions of the total volume fractions were not acceptable. In this study a new method combining gamma densitometry and 3-way partial least squares regression was applied in order to improve the quantitative estimation of the total volume fractions gained in the previous study. The proposed 3-way regression approach allows prediction of the total volume fractions directly using one model instead of multiple models which was reported earlier. The improved quantification of the volume fractions of gas, oil and water was used to improve the flow regime identification plots and increase the interpretability.The new 3-way prediction results for the volume fractions were significantly better than what was found earlier based on individual PLS models. The root mean square error of prediction for gas, oil and water from the 3-way PLS models were 4.1 %, 4.3 % and 4.6% respectively. All models reported were validated based on independent data (test set validation).     

二通插装阀非线性动力学行为

为研究二通插装阀主阀芯在压力脉动条件下开启过程中的非线性振动问题,考虑管道容积效应,建立了插装阀主阀芯动态过程的非线性动力学模型,利用MATLAB/Simulink进行了数值仿真。首先根据模型中油源压力不存在脉动项和存在脉动项两种情况,通过时域图以及相图研究了插装阀主阀芯的开启特性;然后,在考虑油源压力脉动的条件下,分析了油源的不同压力等级对插装阀主阀芯动力学行为的影响;最后,针对不同管道长度,研究了管道长度对插装阀主阀芯动力学行为的影响。结果表明：油源压力脉动会引起插装阀主阀芯出现振动行为;在相同油源压力脉动条件下,随油源压力增大,主阀芯振动行为减弱,不易发生碰撞行为;泵出口到阀组间管道长度越长,主阀芯越容易发生非线性振动行为,并伴随着阵发性振动行为的产生。研究结果为探究大型插装阀的失稳机理提供了理论依据。     

基于正交的二次分离旋流器结构优选数值分析

一体化二次分离旋流器是在单体旋流器内部进行二次分离的一种新型旋流器。利用正交法,基于计算流体动力学软件,分别对一级溢流管长度、圆柱段长度、二级溢流管伸入长度、二级锥段角度、底流管长度等结构进行优选。设置油相体积分数为2%、油滴粒径为30μm的混合液作为研究介质。首先采用单一指标的方法找出分离效果最优的结构,然后将优选后的结构与初始结构进行了对比验证。此方法可为水力旋流器的结构参数优选提供参考。     

Measurement of high-water-content oil-water two-phase flow by electromagnetic flowmeter and differential pressure based on phase-isolation

When the oil field has been exploited by long-term water-flooding, it will be in high water-content stage of production. However, it is a great challenge for high-water-content measurement due to oil droplets extremely dispersed in the water. In this paper, we developed a phase-isolation based method for high-water-content oil-water two-phase flow measurement. Phase-isolation was realized by axial-flow swirler to concentrate scattered and random oil droplets into the pipe center and change the inlet flow pattern into a particular annular flow before measuring. Owing to the axisymmetric velocity and phase distribution, the electromagnetic flow meter avoided the effect of random distribution of insulating phase, and then had a good measurement performance for total volume flow rate. Furthermore, we respectively studied using axial pressure drop, radial pressure drop and the ratio of the two pressure drops to measure water content. The results showed that the ratio of the two pressure drops not only improves the resolution of oil and water, but also effectively reduces the impact of error transfer. In the dual-parameter measurement experiment, the relative errors of total volume flow rate and water content were almost within ±5%.     

基于ECT对油气润滑中油膜厚度的研究

油膜厚度是评价油气两相环状流的重要指标.论文利用ECT电容层析成像传感器,在油气润滑实验台上,研究了不同单次供油量下水平输油管内的油气两相流油膜厚度变化规律.实验结果表明：随着供油量的逐渐增大,油膜厚度经历了从极薄且不稳定,到油膜较厚相对稳定,到油量沉积、流型变化的过程;在供油量较小的时候,油膜在弯曲管路容易断裂,当供油量较大时,油膜容易在弯曲管路发生堆积.     

一种新型的电容式油气两相流相份额传感器

本文介绍了一个高精度的电容式两相流相份额传感器。该传感器是非插入式,传感部件与测量电路集成一体,排除了寄生电容和杂散电容的影响,使测量精度和稳定性大大提高;输出是直流电压信号,便于计算机自动采集数据;动态反应快,适于实时在线测量。可用于管内油气两相流相份额测量、流型识别、两相流量测量和流动状态监测     

Imaging stratifying liquid–liquid flow by capacitance tomography

Electrical capacitance tomography offers a non-intrusive technique for on-line visualisation of two-phase liquid–liquid flows. It has been applied on a facility which provides metered flows of water and kerosene to a test section at the start of which they pass through a dispersing multi-hole orifice plate. The test section consists of a sudden expansion with an internal diameter of 63 mm inlet and 100 mm outlet and which can be inclined. Beyond this the mixture is separated into the two constituents and returned to their individual tanks. Tomography measurements were made using a PTL-300 electronic system coupled to a 12-electrode sensor which was built in-house. The sensor is fitted on the outside of one of the plastic pipe lengths of the test section. By varying the input oil fractions from 20% to 70%, using mixture velocities of 0.2, 0.3, and 0.4 m/s and positioning the pipe at angles of +6,+3,0, −4 and −7 to the horizontal, different flow patterns were established in the test section. A specially developed calibration method is used in all experiments and tomographic images of the stratifying liquid–liquid flow were obtained. These images show clearly that the spatial distribution in a pipe cross-section is strongly dependent on the mixture velocity and the distance from expansion in the range studied. Concave interfaces were observed in horizontal and downward inclination flow for all cases while convex interfaces were identified only in an upward inclination flow at the high input oil fractions and high mixture velocities. This application illustrates very clearly the capability of the ECT for on-line imaging of liquid–liquid two-phase flows.     

Multiphase flow measurements using coupled slotted orifice plate and swirl flow meter

Multiphase flow metering is a major focus for oil and gas industries. The performance of a modified version of a close coupled slotted orifice plate and swirl flow meter for multiphase flow was evaluated to provide further development of a new type of multiphase flow meter. The slotted orifice provides well homogenized flow for several pipe diameters downstream of the plate. This characteristic provides a homogeneous mixture at the inlet of the swirl meter for a wide range of gas volume fractions (GVF) and flow rates. In order to evaluate the performance of the designed flow-meter, its response was investigated for varying pressures and water flow rates. The proper correlations were established to provide high accurate two-phase flow measurements. The new proposed approach provides the GVF measurement with less than ±0.63% uncertainty for GVF range from 60% to 95%.     

油气润滑管道环状流形成及影响因素研究

建立了油气润滑系统中内径为6 mm的水平管模型,利用FLUENT仿真软件对管内油气两相环状流进行了数值模拟,研究分析了油液速度、气体速度对环状流质量的影响。结果表明,气体速度是影响环状流质量的主要因素,在油量一定时气体速度为60 m/s~80 m/s时形成的环状流品质较好。     

硬齿面减速机的润滑

硬齿面减速机目前得到广泛的使用.减速机的润滑直接影响到减速机使用的寿命.为此从润滑机理出发,介绍了如何选用润滑油,润滑油量的大小及进出油口管径的计算方法.