稠油热采井下湿蒸汽温度、压力和干度一体化测量新方法研究

Steam quality is affected by many factors such as temperature, pressure and so on, whose accurate measurement is always an international difficult problem. Aimed at a fact that the measurement cycle of steam quality is too long for manual sampling method in heavy oil thermal recovery, a novel method of steam quality is put forward in this project. The refractive index of wet steam is measured by means of photonic crystal fiber based on surface plasmon resonance (SPR) technolgoy, at the same time, the temperature and pressure in situ for the measurement condition are gauged by using tilted fiber Bragg grating (TFBG),thus the steam quality can be obtained through the three parameters above mentioned. This project creatively concentrates upon the structure design of photonic crystal fiber SPR, and the influence factors of the optical spectrum characteristics and corresponding changing rules are systematically investigated by means of theoretical simulation, and then a design standard for structure optimization of the sensors is obtained.It is emphasized that the preparation processes of nano-sensing metal thin films are studied for photonic crystal fiber SPR, and internal physical mechanisms of the influence of process parameters and microstructure of the thin film on the optical spectral characteristics are clarified for photonic crystal fiber SPR. In addition, the internal links between refractive index of wet steam and resonant wavelength are also clarified. At last, combined with the values of temperature and pressure obtained by TFBG, the relative thermodynamic parameters of wet steam can be known through standard data base of water and steam, and then the steam quality can be determined. Therefore, the integrated measurement of temperature, pressure and steam quality can be realized in this project, and a novel method is provided for mastering downhole steam injection conditions in time.

湿蒸汽干度因受温度和压力等多种因素的影响，其准确测量始终为一国际难题。本项目针对稠油热采领域人工取样测量干度周期过长的问题，提出采用光子晶体光纤表面等离子体共振(SPR)技术测量湿蒸汽折射率，同时借助倾斜光纤布拉格光栅(TFBG)传感器原位测量蒸汽温度和压力，综合运用上述三参数获得干度的新思路。创新性地围绕光子晶体光纤SPR传感元件的结构设计，通过理论仿真的方法系统考察光子晶体光纤SPR传感特性的影响因素及变化规律，建立传感元件结构设计优化准则；重点研究光子晶体光纤SPR传感所用金属纳米薄膜的制备工艺，阐明工艺参数和薄膜微观结构对光子晶体光纤SPR光谱特性影响的物理机制，揭示湿蒸汽折射率与SPR谐振波长之间的内在联系，确定湿蒸汽的折射率，然后结合TFBG所测得的温度和压力信息查知湿蒸汽的相关热力学参数，求得干度，实现井下湿蒸汽温度、压力和干度的一体化测量，为实时了解井下注汽状况提供新方法。

稠油热采蒸汽干度的准确测量始终为一国际难题，本项目针对人工取样测量干度周期过长的缺点，主要利用光子晶体光纤表面等离子体共振(SPR)传感器和倾斜光纤布拉格光栅(TFBG)传感器原位测量蒸汽温度、压力和干度，提出一种光纤集成多参量测量的新思路。围绕光子晶体光纤SPR传感结构的设计与优化，创新性地提出多孔多芯型、高双折射型、双开口环型、圆形待测介质通道型等多种光子晶体光纤传感结构，系统考察光子晶体光纤结构参数如空气孔尺寸、间距、纤芯尺寸、金、银、石墨烯等薄膜及其厚度等参数对共振光谱的影响，研究传感器振幅灵敏度、光谱灵敏度的影响因素及其变化规律，揭示光子晶体光纤SPR光谱特性的内在物理机制，建立传感器结构设计优化准则；深入探索传感器对介质折射率的响应关系，阐明折射率与SPR谐振波长之间的内在联系，传感器最高灵敏度可达13000nm/RIU，共振波长在可见光和红外光范围内调控，最大共振波长处于2550nm-2900nm中红外区间，传感精度可达7.69×10-6 RIU；提出一种光子晶体光纤SPR温度传感器，在0℃- 100℃范围内，其平均温度传感灵敏度为3080 pm/℃，线性度为0.9984，传感器温度分辨率高达0.03125℃；利用超连续光源、ASE宽带光源、光纤光谱仪、光纤偏振器、光子晶体光纤SPR传感器及高温高压蒸汽发生器等装置搭建实验传感测试系统，对样机进行不同温压环境下测试；基于水蒸汽热动力学理论模型，结合水和水蒸汽ISPWS97数据资料，调取压力、温度、比容、比熵等信息，基于比容(密度)、波长、折射率三者之间的Lorentz-Lorenz函数关系，利用Matlab语言编制资料解释程序，构建湿蒸汽温度、压力、干度一体化资料解释模型，实现稠油热采井下湿蒸汽温度、压力和干度的一体化测量，为实时了解井下注汽状况提供新方法。在研究期内共发表论文30篇，其中SCI收录24篇，TOP期刊2篇，申请发明专利5项，授权实用新型专利3项，参加学术交流会议6次，培养博士生1名、硕士生4名。