螺旋天线原油含水率测量仪的误差分析与校准

天线是射频法原油含水率测量仪的关键部件。分析采用平行天线和螺旋天线的含水率测量仪在检测原理上的差异,使用研制的螺旋天线原油含水率测量仪进行含水率重复性实验,实验数据分析表明,含水率在40%-80%时,由于原油发生相变,在该区间,含水率测量仪的线性度变差。针对上述问题设计含水率测量误差校准方法及流程,采用分段线性插值法进行含水率全区间测量误差校准,在模拟管道平台和油田井场进行多次重复实验。实验结果表明:所研制螺旋天线含水率测量仪可实现全区间含水率测量,和油田仍普遍使用的蒸馏法含水率测量方法相比,含水率测量误差在5%以内。该仪器可为数字化油田、智能分层采油和注水提供含水率测量数据。     

基于随机森林算法的井下原油含水率软测量方法

井筒产出液实时测量是获得井下产液信息的关键步骤,是实现智能井的重要前提,但由于井下环境的复杂性,油水混合物状态本身的不确定性,缺少较好的方法能在井下较好地完成产出液各成分含量的计量。针对井下油、水两相混合计量的问题,提出了一种结合机器学习算法的井下原油含水率软测量方法。结合采油工程需要,可将原油含水率以10%的间隔划分成11个类别,将不同原油含水率对应的物理属性作为测量对象,利用随机森林算法对已知样本进行学习分类,得到原油物理属性与含水率之间的关系,进而实现对原油含水率的测量。最后,通过设计的室内实验,对提出的软测量方法进行了验证,结果表明利用该方法预测原油含水率,得到的结果与实验值一致,可以初步满足工程对井下原油含水率测量的需求,为井下测量提供一了种新的思路。     

基于多极板电容传感器测量原油含水率的研究

设计了测量原油含水率的多极板式电容传感器及测量电路;建立了多极板式电容传感器测量原油含水率的数学模型,得到了原油含水率变化量与多极板式电容传感器等效电容变化量之间的函数关系.进行了五极板式电容传感器和单极板式电容传感器测量油水混合物含水率的对比实验.实验结果表明采用五极板式电容传感器测量油水混合物的含水率,相对于采用单极板式电容传感器测量油水混合物的含水率的测量精度有大幅度的提高;而且采用五极板式电容传感器测量油水混合物的含水率,无论是在低含水率端还是在高含水率端其测量结果都比较稳定.     

油田联合站自动盘库计量技术研究

本文提出一种基于测量罐中原油平均含水率的自动盘库计量方法，推算出用此法进行自动盘库的数学模型，并分析了盘库中平均含水率测量和净油质量测量的不确定度。实验结果表明，此设计方案适用于油田联合站和油库罐区的自动盘库。     

原油科里奥利质量流量计检定系统的设计和应用

随着质量流量计在油田分队计量的广泛应用,质量流量计的作用得到了使用单位的认可,质量流量计的使用基本上达到了预期的效果,起到了分队计量的作用。由于用于分队计量的质量流量计在运行一段时间后会在测量管内壁结垢,从而影响其测量的准确性,需要重新检定确定新的流量系数和密度系数。目前国内的检定机构的质量流量计检定装置基本上是针对以成品油为介质的质量流量计而设计的,不能满足用于测量油水混合液的质量流量计检定需要。文章通过设计一种新的检定系统实现对原油科里奥利质量流量计的清洗、检定,对流量误差和密度误差进行修正,最终实现原油质量流量计的准确计量。     

基于同轴线相位法的两相流含气率测量研究

为了准确测量气液两相流含气率,提出一种同轴线相位差测量方法。利用同轴线传感器,通过测量电磁波经过在同轴线内分布状况不同的气液混合介质后相位差的变化,得到混合介质的含气率。完成了同轴线测量电路及测量传感器的设计,建立了一种含气率测量模型。以气液两相做了室内静态实验,并对垂直管状态下传感器响应和实验结果进行了误差分析。结果表明:相位差输出与含气率呈线性关系;同时,在不同频率下,预测结果和实验结果的相对误差在±5%范围内,说明预测模型准确度较好。     

石油水分接受器校准方法研究

<正>为保证原油含水率数据的准确可靠,在原油交接等环节,根据国家标准,原油实验室多数采用人工蒸馏法作为检测原油含水率的方法。实验人员在实际检测中通过对所用蒸馏设备进行分析,发现存在多种影响测量结果准确性的因素,一般来说,容量校准问题和使用不当是产生误差的主要原因。以下就GB/T8929-2006《原油水含量的测定蒸馏法》中所用蒸馏     

新型测量传感器技术在油罐剖面监测中的应用

在油田生产中,原油沉降罐中油水界面及液位的准确测量对于油田的正常生产有着重要的作用。目前的油罐液位及油水界面测量装置误差较大,文章提出通过逐点阻抗测量技术这一全新的测量方法来提高液位及油水界面的测量精度,从而精确计量油罐中油层的厚度,为生产工艺的调整及相关部门的决策提供可靠依据。     

原油含水率的红外光谱快速检测技术

该文旨在探索一种基于红外光谱技术的原油含水率快速检测方法,研究采用油田提供的3种MDT取样流体原油样本,每种原油制备5种含水率、5种矿化度,共计75个不同属性的油水乳状液。采集75个配制样本的红外光谱,进行波长筛选并用"一阶导数+减去一条直线+SG卷积平滑(17)"法对光谱进行预处理,对谱图进行分析,并用偏最小二乘法建立关于原油含水率的定量检测模型。最终建模相关系数R达到94.44%,交互验证均方根误差RMSECV为4.11,相对分析误差RPD为3.04;预测相关系数R为83.54%,预测均方根误差RMSEP为7.44,模型稳健性良好。研究表明红外光谱检测技术对于原油含水率检测具有可行性,为光谱技术应用于原油含水率在线检测奠定了基础,可为测井勘探技术提供一种新的途径。     

剪切条件下油水乳状液含水率测量装置的设计

针对传统油水乳状液含水率测量装置的准确性低、成本高、无法实现动态测量的问题,设计一种剪切条件下乳状液含水率的测量装置。系统利用油水两相的介电及电导特性的差异性,采用交流阻抗法测量待测乳状液的复阻抗参数,从而获得乳状液的含水率特征。结合搅拌装置模拟油水乳状液在运输环境下的剪切环境,间接实现油水乳状液的动态测量。实验测试表明:装置具有良好的重复性和稳定性,可实现剪切条件下对乳状液复阻抗参数的测量,证明乳状液的阻抗参数与含水率存在明显的线性关系,对进一步研究管道中油水两相的流动性质具有一定的参考价值。     

Analysis of an open-ended coaxial probe with lift-off fornondestructive testing

The open-ended coaxial probe with lift-off is studied using a full-wave analysis, and an uncertainty analysis is presented. The field equations for the following terminations are worked out: (1) the sample extends to ∞ in the positive axial direction, (2) the sample is backed by a well-characterized material, and (3) the sample is backed by a short-circuit termination. The equations are valid for both dielectric and magnetic materials. The model allows the study of the open-ended coaxial probe as a nondestructive testing tool. The analysis allows a study of the effects of air gaps on probe measurements. The reflection coefficient and phase are studied as a function of lift-off, coaxial line size, permittivity, permeability, and frequency. Numerical results indicate that the probe is very sensitive to lift-off. For medium to high permittivity values and electrically small probes, gaps on the order of fractions of a millimeter strongly influence the reflection coefficient. In order for the field to penetrate through the air gap, larger size coaxial line or higher frequencies need to be used. A comparison of the theory to experiment is presented. The results are in close agreement. A differential uncertainty analysis is also included     

Dielectric measurements of frozen silt using time domain reflectometry

Dielectric properties of ice-rich frozen silt from the permafrost tunnel at Fox, Alaska, have been measured both in the field and in the laboratory, using time domain reflectometry (TDR). Undisturbed field samples obtained with a modified CRREL core barrel were placed in a specially adapted rigid coaxial line mated to the TDR unit. The volumetric water content of the undisturbed samples varied between 65 and 81% and the sample temperature was approximately ?7.0°C. The laboratory samples were reconstituted with volumetric water content between 0 and 55%. Temperature was varied between +25° and ?25°C. The data were processed to cover the frequency range of 0.05–1.0 GHz. For the undisturbed samples, dispersion tended toward a maximum between 0.3 and 1.0 GHz. The range for the real part of the dielectric coefficient was 3.8–5.3 at the low frequency end, while the imaginary part varied between 0.01 and 0.42 for the entire frequency range. These results from the field studies agree with laboratory measurements and other field observations, indicating that the TDR core barrel sampler is an effective technique for measuring dielectric properties of undisturbed samples. This method could easily be applied for in situ dielectric testing of frozen fine-grained soils and ice.     

Use of Microwaves for the Detection of Water as a Cause of Corrosion Under Insulation

Corrosion under insulation is a significant cause of pipeline failure in the oil and gas industry. This paper describes the initial developmental stages of a technique which uses the structure of an insulated pipeline as a coaxial waveguide to support the propagation of microwaves. These microwaves are used to inspect the insulation layer for the presence of water, which will indicate the regions of the pipe at risk from corrosion. The practical requirements to achieve a low coherent noise level are identified, and the structures and dispersion characteristics of the modes which propagate in coaxial waveguides are examined to determine if these requirements can be met. An antenna array design proposed for pure mode excitation of the TEM mode and its effectiveness is demonstrated experimentally on a 12″ diameter coaxial waveguide. In particular, a signal-to-coherent-noise ratio as high as 39 dB is obtained with this arrangement. The sensitivity of the technique to the presence of water within the waveguide is investigated and it is found that water volumes with a cross-sectional area in the plane perpendicular to the waveguide axis of as little as 5% produce reflections that are readily detectable from the coherent noise floor.     

高功率微波器件均衡网络的设计、应用与理论分析

针对高功率微波器件工作频带内增益波纹大的问题，结合不同用户的需求和具体器件，设计制作了多个吸收型同轴谐振腔在同轴传输线上多级级联型的均衡网络，并作出谐振腔内电磁场的理论分析。最佳均衡效果为对一高功率行波管在Ku波段300MHz带宽内，将12dB的增益波纹均衡至0.35dB。     

Heating and Melting of Paraffin in a Coaxial System under the Effect of High-Frequency Electromagnetic Radiation

The impact of a microwave electromagnetic field on the melting of paraffin in a coaxial system simulating an oil well is investigated. The schematic diagram is presented of the experimental facility for the investigation of melting of paraffin in a system consisting of an internal pipe and a coaxially arranged external pipe. In the interelectrode space of these two pipes, an electromagnetic field is induced with a frequency of 2400 MHz. It is shown that the distribution of temperature in the pipes is nonuniform, corresponding to the standing electromagnetic wave in the interelectrode space. The presence of paraffin in the interpipe space substantially accelerates the melting process in the entire coaxial system.     

A study on the coaxial aperture electromagnetic sensor and itsapplication in material characterization

An open-ended coaxial line has been studied by many researchers in order to use it as an electromagnetic sensor for the characterization of materials. These studies include static as well as quasi-static formulations under various simplifying assumptions. In this paper, we use a full-wave formulation of the problem and solve an integral equation to evaluate the aperture field distribution. The electromagnetic field distributions in the material medium as well as the aperture admittance are evaluated subsequently. The effects of a conducting flange over the coaxial opening and the finite sample size are also studied. The results are compared with the experimental data as well as the data obtained by other approaches. An application of this coaxial sensor for the characterization of materials up to 40 GHz is demonstrated     

A new microcalorimeter for measurements in 3.5-mm coaxial line

A new microcalorimeter has been realized for implementing the national power standard up to 26.5 GHz in a 3.5-mm coaxial line at the Istituto Elettrotecnico Nazionale (IEN) Galileo Ferraris, Turin, Italy. The system is based on a dry thermostatic cell controlled by Peltier elements. The thermal load consists of a twin sensor system that is alternately supplied with high frequency test power and low frequency or direct current (DC) reference power through adiabatic coaxial lines. This microcalorimeter was originally designed for calibrating bolometric mounts. Recently, it has been modified for thermocouple power sensors, which can operate from DC to 26.5 GHz in a 3.5-mm coaxial line.     

异形吉赫横电磁波室场强装置

根据非对称矩形同轴线原理研制了宽带吉赫横电磁波室。采用独特的异形结构，扩展了小室内的有效使用空间。应用有限元法、有限积分技术和时域有限差分法对小室的特性阻抗、电压驻波比、场分布进行了仿真计算，解决了结构设计、输入转接头阻抗匹配、吸波材料的选型等关键技术。文中给出小室在10kHz～18GHz频率范围内的性能指标测试结果。该装置具有宽频带、大功率等特点，可用于高场强辐射抗扰度试验和场强校准。     

Complex permittivity and moisture measurements of oil palm fruits using an open-ended coaxial sensor

An open-ended coaxial sensor for the determination of complex permittivity and moisture content of oil palm fruits is presented in this paper. The measurement system consisting of the sensor and a PC-controlled vector network analyzer have been tested successfully on a range of oil palm fruits of various degrees of ripeness. The initial values of the complex permittivity were estimated using the admittance model of the sensor. The amount of moisture content was found by matching the values of permittivity from the quasistatic model with the permittivity of a dielectric mixture model using the moisture content values obtained from the standard oven drying method.     

Experimental Characterization of a Singly Loaded E-Plane Waveguide Post by Using a Tunable Coaxial Line

Equivalent-circuit parameters of a singly loaded E-plane waveguide post have been experimentally measured by loading one end of the post with a tunable coaxial line. The resulting structure shows a transmission minimum and a transmission maximum. The positions of the movable short for minimum and maximum transmission have been correlated with the parameters to be measured. It is seen that the errors due to uncertainty in the length measurement can be minimized through the use of a coaxial line with the highest feasible characteristic impedance. Agreement between theoretical and experimental results is satisfactory.