STABILITY OF COAL WATER PUEL

Abstract

In this paper, a novel sensor is presented for monitoring the stability of a coal water fuel. This sensor utilizes a non-radioactive electromagnetic source, making it more attractive in comparison to other existing sensors. It utilizes the interaction between the electromagnetic waves and the CVF composition. Two of these interactions are selected, namely, the transmitted and reflected signal, and are used to give an indication on the stability of the CVF. The sensor measures the concentration changes or structural variations in the CVF. Calibration of the sensor is performed, for a given pipe/tube and a given CVF, by changing the concentration of the CVF and recording the transmitted and refelected signals as functions of concentration. These calibration curves are then stored in a microcomputer. At any instant of tine, the CVF stability is measured by comparing the sensor response to the stored curves. This sensor is easy to use and is readily adapted for automation. To demonstrate the applicability of the technique, the sensor response is measured and calibration curves are extracted and presented here. In this paper, four commonly used stability measurement techniques are also discusse     

双发单收谐振型电磁波测井线圈系刻度方法研究

增大源距是提高随钻电磁波电阻率测井仪器探测深度的有效方法,但是接收信号随源距增大严重衰减。本文将谐振原理引入随钻电磁波电阻率测井,采用双发单收谐振型线圈系结构,提高接收线圈的电压幅度。实验室通常采用刻度环模拟地层电导率,开展仪器响应特性研究。双发单收谐振型线圈系的刻度方法与传统的开路线圈系结构完全不同。本文基于DOLL几何因子理论,对双发单收谐振型线圈系刻度环参数选择方法进行研究,发现参数选择应该兼顾相对平稳度与刻度环电阻分辨度,以减小测量误差。实验比较了均匀地层中接收线圈开路和谐振响应特性,表明谐振方法只增大了接收响应的幅值而没有改变幅度比,验证了刻度环参数选择方法的正确性以及谐振方法的正确性。     

多传感器优化标定方法研究

提出一种多传感器标定的优化方法，它充分融合标定仪表和所有待标定传感器的信息，使传感器标定过程简化，而且标定后的传感器的测量精度在本能满足要求。该方法包括两个部分：传感器特性曲线的斜率函数近似线性化处理，和建立基于传感器输入输出特性曲线的目标函数，并利用梯度法实现目标函数的优化。实验结果证实，该方法简捷有效，达到了保证和提高传感器测量精度的目的，因而具有一定的实用价值。     

高频电磁波测井的灵敏度分析与特征识别方法(Ⅱ)——用测井曲线提取地层参数的方法

基于对高频电磁波测井响应特征的认识 ,提出了一种利用相位差和幅度比测井曲线提取地层参数的特征识别方法 ,即利用测井响应对地层深度的相对一阶导数绝对值曲线的极大值峰的位置来确定地层的纵向边界 ,由其极小值处的测量值来确定地层的电参数视值 ,这样得到的结果是比较好的     

JHPZ-高温高压智能型膨胀性测试仪的研制

介绍了ＪＨＰＺ－高温高压智能型膨胀性测试仪的组成、工作原理以及使用方法。仪器的膨胀腔设计成多腔压力平衡式结构,保证了测量头与试样的接触。试验时,膨胀量通过位移传感器传给数据采集器,再由计算机存储、处理,并打印数据报告和膨胀曲线。同时仪器的双测试头设计提高了试验效率,室内试验证明仪器性能稳定,数据规律性强,可用于井壁稳定性研究。     

钻井泵压力及阀体位移规律的微机测试系统

钻井泵阀工作性能的好坏直接影响钻井作业能否顺利进行。为对钻井泵阀的运动学和动力学性能进行研究，建立了由计算机、传感器、信号放大器、激光器、A／D接口等组成的微机测试系统。介绍了钻井泵压力、阀体位移规律及活塞死点的在线测试原理和方法；同时介绍了位移传感器的制作原理和方法，以及对测试信号进行滤波、放大的处理手法，最后给出了实测曲线。对这种测试系统稍加改造，即可用于对钻井泵进行故障珍断等方面的研究。     

瞬变电磁测井信号自适应相干积累检测方法

受井下高温、高压以及运动测量等复杂测试条件的影响,低信噪比一直是困扰井下瞬变电磁探测系统发展的主要因素之一。针对这一问题,在柱状多层非均匀模型基础上,提出了一种瞬变电磁测井信号自适应相干积累检测方法。利用运动测量过程中相邻周期瞬变电磁响应的相关性,通过计算不同周期响应差异的Frobenius范数实现自适应相干积累。现场试验结果分析表明,该方法能够有效改善井下瞬变电磁系统信噪比,比固定时间相干积累具有更好的井下复杂环境适应能力。     

Resonant microwave sensors for instantaneous determination of moisture in foodstuffs

Open microwave resonators are very well suited for online moisture monitoring during the production of foodstuffs. In order to allow for rapid measurements, the required information is derived from the dielectric behaviour of the material. Unlike for example the method of Karl Fischer titration, the dielectric microwave method determines the moisture content indirectly and is thus dependent on density changes. The present paper outlines special features of open resonators for density independent moisture measurement. It is demonstrated, how unfavourable design of the window for coupling out the fringing field of the open resonator leads to non-linear behaviour of the characteristics of resonant frequency and reciprocal quality factor vs density and moisture changes. Several engineered open microwave moisture sensors are presented and discussed. More in detail, a surface sensor, a surface sensor equipped with a small container on top, a self contained hand-held surface moisture sensor and a grooving-probe as well as a multi-hole sensor are shown. The electronics and the signal processing of the sensors are briefly described. Finally experimental moisture measurements and a density independent calibration are given for rolled oats. Moisture measurements on whole kernels of oats, barley and wheat demonstrate the only weak dependence of the microwave moisture measurement approach on the special type of material.     

双感应测井基值大小对感应曲线的影响

介绍了SL1503感应测井仪的现场刻度原理和感应测井基值的调试方法。从仪器的角度对感应测井曲线产生异常现象的原因进行了理论上的推导和分析，并用实例验证了感应测井曲线异常的原因是由于感应测井调试不当以及刻度不及时造成的。针对感应测井曲线的这些异常现象，系统地总结了一套感应测井基值的调试方法。最后，对感应测井仪的现场刻度和调试提出了自己的建议。     

聚驱配注井测试流量校正方法及应用

为解决存储式电磁流量计在聚驱配注井中测试流量与实际注入流量的差异问题,通过模拟井中的实验研究,在总结仪器响应规律的基础上,提出了在清水中刻度的电磁流量计应用于聚驱配注井中测试流量时的校正方法.现场应用表明在油管结垢较轻微的井中,该校正方法很好地解决了存储式电磁流量计在聚驱配注井中测试流量与实际注入流量的偏差问题;在投注时间较长的井中,由于油管内壁结垢、腐蚀等原因,使得该校正方法的应用效果受到限制.     

振动管式流体密度传感器研究

介绍一种应用于井下自由衰减振动式流体密度传感器.传感器基于管内流体密度与管自由衰减振动周期的非线性关系理论,采用独特的电磁激振和动圈检振的激、检振方式,以PIC16F87X微处理器为核心,配合少量模拟电路完成流体密度的测量,并提供曼彻斯特编码输出/输入和模拟输出方式与外界进行接口.实验结果表明,流体密度与振动管的自由衰减振动周期成近似线性的函数关系,其非线性程度是由传感器的形状和材料参数决定的;随着振动管内流体密度的增加,其振动管自由衰减的振动周期也增加.这种机电一体化的流体密度传感器在井下应用时必须进行井场刻度以及温度和压力的校正.     

随钻测量数据的井下短距离无线传输技术研究

在随钻测量和随钻测井技术中，近钻头传感器测量数据的传输一直是个难题，为此，提出了用电磁感应电流场建立短距离无线传输信道的方法将近钻头传感器测量数据跨井下马达传输，或遥控无法穿线缆的井下工具。分析了建立无线短传信道的原理，介绍了关键部件的设计和无线短传通信机的工作过程，以厦无线短传系统的试验情况和试验结果。     

Crude oil UV spectroscopy and light scattering characterization

Crude oil is a complex mixture of hydrocarbons representing several classes of compounds. Some of these constituents significantly affect refinery processes and analysis procedures. Ultraviolet-visible (UV-vis) spectroscopy has received wide acceptance because of its broad scope, given that many active species in the spectrum of UV, and many more that with proper treatment, are able to form visible species in that spectrum. In this study two crude oils from different sources were analyzed without dilution C1-RC, in the coastal region and C2-RM of the maritime region of the Gulf of Mexico. Stages for obtaining calibration curves depending on the change in concentration of crude, starting from crude standard solutions and evaluating the repeatability of the method and the dispersion, were established. The results show three signals: (a) 230 nm corresponding to benzene compounds, (b) 260 nm to naphthenic compounds, and (c) 410 nm Soret band corresponding to the metal porphyrins. These species are found in asphaltenes, signals were evaluated individually for separate calibration curves, at concentrations between 10 and 90 mg L^?1. The model equation of each curve based on the absorbance and concentration determination coefficient values for each compound are reported. It was possible to establish that the method developed is suitable for oil solutions at low concentrations.     

双感应电阻率反演研究及在吐哈油田的应用

电阻率反演是电测井曲线校正的重要方法。双感应测井在油田现场应用非常普遍,其数据反演属于非均匀介质中电磁波逆散射问题范畴。在旋转轴对称地层模型条件下,正演采用数值模式匹配法（ＮＭＭ）,反演用变形的Ｂｏｒｎ 迭代法（ＤＢＩＭ）,利用双感应测井曲线逐层进行地层电阻率和侵入半径的反演计算,从模型处理和吐哈油田实际资料处理结果看,效果较为理想,预示了双感应测井反演处理良好的应用前景     

高频电磁波测井的快速正反演

我国东部大多数油田已进入注水采油阶段 ,注入水侵入储集层 ,造成电导率异常 ,给测井解释带来困难。目前 ,采用电磁波测井仪器测量相位差和幅度比 ,利用近似公式将其转换为视电导率和视介电常数 ,再通过图版校正 ,即可得出地层的真电导率和真介电常数 ,使得定量解释的精度得到提高。然而这种图版校正法存在一定的局限性 ,尤其对于薄层 ,由于井眼、围岩及侵入影响的紧密耦合性 ,使得逐次图版校正方法失去作用 ,甚至可能得出错误的结果。因此 ,基于电磁场Maxwell方程的反演方法成为当前电法测井研究的焦点。文中正演采用数值模式匹配方法 ,利用47MHz电磁波测井的相位差和幅度比曲线 ,给出了反演地层真电导率及介电常数的一种快速迭代反演方法。通过对一个 8层模型的无噪声和有噪声数据的反演考查 ,以及通过实际井的反演结果验证 ,其反演结果与模型的响应曲线及实际曲线均吻合较好 ,表明此方法能有效地克服井眼、注入水侵入和邻层的影响 ,所测得的电导率和介电常数接近地层的真实性。该方法精度高 ,应用方便 ,处理油田实际资料效果较好。     

用分维模型定量表征储集层非均质性（为庆祝青海油田勘探开发50周年而作）

利用压汞曲线计算出来的分数维来定量表征储集层微观孔隙结构的非均质性；提出“基于盒维数的测井曲线刻度线网格加密法”，利用单砂体测井曲线计算的分数维来定量表征储集层层内及层间等宏观非均质性。最后，按照同一微相、同一单砂体层位将储集层微观分维与宏观分维联系起来建立储集层分维模型，从而实现了将微观非均质性的定量表征扩展到单砂体规模的宏观非均质性的定量表征。结合实际以某注水开发中后期油田的河流相砂岩储集层为例展开研究，应用效果较为理想。     

振弦式压力传感器数据采集接口设计

振弦式压力传感器采用单芯钢丝电缆测压，其信号可以长距离传输，测量电路可以放置地面进行检测。文中给出了一种适合于ＰＣ机接口的数据采集电路，由于采用了有源ＬＣ谐振放大电路，增强了接口的抗干扰能力。本接口已用于“ＳＬ－９２环空数字测井系统”中，并完成了几十口井次的测试。现场应用表明，本接口简单、可靠、测试精度高，为压力测量从人工解释变为计算机数字化记录、计算机自动解释处理创造了条件。     

一种新型陀螺测斜仪的硬件设计及其误差补偿技术

地磁异常的情况下,钻井或地质钻探必须使用不受磁力影响的陀螺测斜仪.介绍了双转子电磁补偿挠性支承陀螺测斜仪的原理和特点,研究了其专用硬件电路及误差补偿技术.实验表明,陀螺电源、传感器稳频稳幅电路和力矩伺服回路设计合理;通过数据处理方法对陀螺仪漂移进行补偿,使方位测量精度大为提高.设计基本满足测井的实际需要.     

Empirical relations between rock strength and physical properties in sedimentary rocks

In this study, 31 empirical equations are summarized that relate unconfined compressive strength and internal friction angle of sedimentary rocks (sandstone, shale, and limestone and dolomite) to physical properties (such as velocity, modulus, and porosity). These equations can be used to estimate rock strength from parameters measurable with geophysical well logs. The ability of these equations to fit laboratory-measured strength and physical property data that were compiled from the literature is reviewed. Results from this study can be useful for petroleum industry when a range of geomechanical problems such as wellbore stability and in-situ stress measurements should be addressed without direct strength information available. While some equations work reasonably well (for example, some strength–porosity relationships for sandstone and shale), rock strength variations with individual physical property measurements scatter considerably, indicating that most of the empirical equations are not sufficiently generic to fit all the data published on rock strength and physical properties. This emphasizes the importance of local calibration before one utilizes any of the empirical relationships presented. Nonetheless, some reasonable correlations can be found between geophysical properties and rock strength that can be useful for applications related to wellbore stability where having a lower bound estimate of in situ rock strength is especially useful.     

EWR-P4随钻电阻率曲线特殊响应的分析

随着科技的发展和国内市场的需求,随钻测井系统使用越来越频繁。国内许多油田或服务公司均购置了Halliburton生产的随钻测井系统,以提升自己的服务竞争能力。本文主要针对性介绍此套测井系统中的电阻率传感器(EWR-P4)的结构特点及对应分析在实际测量中电阻率曲线的一些特殊响应,以帮助和提高对EWR-P4电阻率曲线的认知能力。