光纤IOFDR分布温度传感及多传感器融合技术研究
发布时间：2018-11-10 18:56
【摘要】：油气井下分布温度与压力测量对于获取油层信息和提高采收率具有重要意义。光纤传感器以其具有的体积小、耐高温高压、灵敏度高和抗电磁干扰等优点正逐步成为智能油井的核心。然而,目前的光纤测井系统仍存在测量参数多样性,系统结构复杂和成本高等问题,针对这些问题,本文对基于非相干光频域反射计(IOFDR)的分布式温度传感器(DTS)以及基于光纤布拉格光栅(FBG)和光纤非本征法布里-珀罗干涉(EFPI)点式温度和压力传感器的多传感器融合技术进行了深入研究。论文的主要工作概括如下；对IOFDR-DTS的测温原理以及空间定位原理进行了理论分析,并在对FBG传感器和光纤EFPI传感器的解调方法以及半导体激光二极管的辐射特性研究的基础上,分别提出了单光源Raman/FBG、Raman/EFPI和Raman/EFPI/FBG三种光纤传感器融合方案,为多参量光纤测量提出了新的解决方法。设计了单模光纤IOFDR-DTS系统,并对系统中的关键技术进行了深入研究。针对单模光纤中微弱拉曼散射光信号检测问题,设计了一种3通道同步射频数字锁相放大器,对相位参考光、后向斯托克斯散射光和反斯托克斯散射光信号进行同时测量,扫描频率范围为1kHz-100MHz。为进一步提高温度分辨率,提出一种自适应动态小波阈值去噪法。其次,对单模光纤DTS中的偏振效应进行了理论和实验研究,通过误差分析推导出了偏振相关测量误差与偏振相关损耗(PDL)和偏振相关响应(PDR)之间的定量关系,计算的偏振相关误差为±4.1℃,与实验测量值±3℃基本吻合。为减小单模光纤IOFDR-DTS系统的偏振相关测量误差,提出一种基于低速光纤挤压式电动偏振控制器的同步扰偏技术。最后,测试了IOFDR-DTS系统的主要性能指标,空间分辨率达到0.93m,温度分辨率达到0.2-C,最大测量距离为5km。本文设计的Raman/FBG融合系统实现了对分布温度与准分布式温度/应变的同时测量。实验结果表明,分布温度测量与准分布温度/应变测量之间没有干扰,分布温度测量的温度分辨率达到0.4℃,FBG准分布式测量的温度分辨率和动态应变分辨率分别达到0,08。C和64nε/(?),且可被FBG复用的光谱范围超过50nnm。此外,针对油井下分布温度与压力同时测量的需求,设计了Raman/EFPI和Raman/EFPI/FBG融合测量系统,并分别采用DTS和FBG温度测量值对EFPI压力测量进行温度补偿,可分别实现5.3kPa和2.1kPa的压强测量分辨率。该方案简化了系统结构,降低了系统成本,为光纤测井技术在油气井开采中的推广应用奠定理论与实验基础。
[Abstract]:The measurement of distribution temperature and pressure in oil and gas well is of great significance for obtaining reservoir information and improving oil recovery. Fiber optic sensor is becoming the core of intelligent oil well because of its small size, high sensitivity, high sensitivity and resistance to electromagnetic interference. However, there are still many problems in the optical fiber logging system, such as the diversity of measurement parameters, the complexity of the system structure and the high cost. In this paper, the distributed temperature sensor (DTS) based on incoherent optical frequency domain reflectometer (IOFDR) and the point temperature and pressure sensor based on fiber Bragg grating (FBG) and fiber extrinsic Fabry-Perot interference (EFPI) are studied. The multi-sensor fusion technology based on the above-mentioned method is studied in detail. The main work of the thesis is summarized as follows; The principle of temperature measurement and space positioning of IOFDR-DTS is analyzed theoretically. The demodulation methods of FBG sensor and fiber optic EFPI sensor and the radiation characteristics of semiconductor laser diode are studied. Three optical fiber sensor fusion schemes, single light source Raman/FBG,Raman/EFPI and Raman/EFPI/FBG, are proposed, which provide a new solution for multi-parameter optical fiber measurement. The single mode fiber IOFDR-DTS system is designed, and the key technology of the system is studied. In order to detect the weak Raman scattering signal in single-mode optical fiber, a three-channel synchronous RF digital phase-locked amplifier is designed to measure the phase reference light, backward Stokes scattering light and anti-Stokes scattering light simultaneously. The scanning frequency range is 1 kHz-100 MHz. In order to further improve the temperature resolution, an adaptive dynamic wavelet threshold de-noising method is proposed. Secondly, the polarization effect in single-mode fiber DTS is studied theoretically and experimentally, and the quantitative relationship between polarization correlation measurement error and polarization dependent loss (PDL) and polarization dependent response (PDR) is deduced by error analysis. The calculated polarization correlation error is 卤4.1 鈩，
本文编号：2323319
[Abstract]:The measurement of distribution temperature and pressure in oil and gas well is of great significance for obtaining reservoir information and improving oil recovery. Fiber optic sensor is becoming the core of intelligent oil well because of its small size, high sensitivity, high sensitivity and resistance to electromagnetic interference. However, there are still many problems in the optical fiber logging system, such as the diversity of measurement parameters, the complexity of the system structure and the high cost. In this paper, the distributed temperature sensor (DTS) based on incoherent optical frequency domain reflectometer (IOFDR) and the point temperature and pressure sensor based on fiber Bragg grating (FBG) and fiber extrinsic Fabry-Perot interference (EFPI) are studied. The multi-sensor fusion technology based on the above-mentioned method is studied in detail. The main work of the thesis is summarized as follows; The principle of temperature measurement and space positioning of IOFDR-DTS is analyzed theoretically. The demodulation methods of FBG sensor and fiber optic EFPI sensor and the radiation characteristics of semiconductor laser diode are studied. Three optical fiber sensor fusion schemes, single light source Raman/FBG,Raman/EFPI and Raman/EFPI/FBG, are proposed, which provide a new solution for multi-parameter optical fiber measurement. The single mode fiber IOFDR-DTS system is designed, and the key technology of the system is studied. In order to detect the weak Raman scattering signal in single-mode optical fiber, a three-channel synchronous RF digital phase-locked amplifier is designed to measure the phase reference light, backward Stokes scattering light and anti-Stokes scattering light simultaneously. The scanning frequency range is 1 kHz-100 MHz. In order to further improve the temperature resolution, an adaptive dynamic wavelet threshold de-noising method is proposed. Secondly, the polarization effect in single-mode fiber DTS is studied theoretically and experimentally, and the quantitative relationship between polarization correlation measurement error and polarization dependent loss (PDL) and polarization dependent response (PDR) is deduced by error analysis. The calculated polarization correlation error is 卤4.1 鈩，
本文编号：2323319
本文链接：https://www.wllwen.com/kejilunwen/shiyounenyuanlunwen/2323319.html
