【摘要】：油氣井下分布溫度與壓力測(cè)量對(duì)于獲取油層信息和提高采收率具有重要意義。光纖傳感器以其具有的體積小、耐高溫高壓、靈敏度高和抗電磁干擾等優(yōu)點(diǎn)正逐步成為智能油井的核心。然而,目前的光纖測(cè)井系統(tǒng)仍存在測(cè)量參數(shù)多樣性,系統(tǒng)結(jié)構(gòu)復(fù)雜和成本高等問題,針對(duì)這些問題,本文對(duì)基于非相干光頻域反射計(jì)(IOFDR)的分布式溫度傳感器(DTS)以及基于光纖布拉格光柵(FBG)和光纖非本征法布里-珀羅干涉(EFPI)點(diǎn)式溫度和壓力傳感器的多傳感器融合技術(shù)進(jìn)行了深入研究。論文的主要工作概括如下；對(duì)IOFDR-DTS的測(cè)溫原理以及空間定位原理進(jìn)行了理論分析,并在對(duì)FBG傳感器和光纖EFPI傳感器的解調(diào)方法以及半導(dǎo)體激光二極管的輻射特性研究的基礎(chǔ)上,分別提出了單光源Raman/FBG、Raman/EFPI和Raman/EFPI/FBG三種光纖傳感器融合方案,為多參量光纖測(cè)量提出了新的解決方法。設(shè)計(jì)了單模光纖IOFDR-DTS系統(tǒng),并對(duì)系統(tǒng)中的關(guān)鍵技術(shù)進(jìn)行了深入研究。針對(duì)單模光纖中微弱拉曼散射光信號(hào)檢測(cè)問題,設(shè)計(jì)了一種3通道同步射頻數(shù)字鎖相放大器,對(duì)相位參考光、后向斯托克斯散射光和反斯托克斯散射光信號(hào)進(jìn)行同時(shí)測(cè)量,掃描頻率范圍為1kHz-100MHz。為進(jìn)一步提高溫度分辨率,提出一種自適應(yīng)動(dòng)態(tài)小波閾值去噪法。其次,對(duì)單模光纖DTS中的偏振效應(yīng)進(jìn)行了理論和實(shí)驗(yàn)研究,通過誤差分析推導(dǎo)出了偏振相關(guān)測(cè)量誤差與偏振相關(guān)損耗(PDL)和偏振相關(guān)響應(yīng)(PDR)之間的定量關(guān)系,計(jì)算的偏振相關(guān)誤差為±4.1℃,與實(shí)驗(yàn)測(cè)量值±3℃基本吻合。為減小單模光纖IOFDR-DTS系統(tǒng)的偏振相關(guān)測(cè)量誤差,提出一種基于低速光纖擠壓式電動(dòng)偏振控制器的同步擾偏技術(shù)。最后,測(cè)試了IOFDR-DTS系統(tǒng)的主要性能指標(biāo),空間分辨率達(dá)到0.93m,溫度分辨率達(dá)到0.2-C,最大測(cè)量距離為5km。本文設(shè)計(jì)的Raman/FBG融合系統(tǒng)實(shí)現(xiàn)了對(duì)分布溫度與準(zhǔn)分布式溫度/應(yīng)變的同時(shí)測(cè)量。實(shí)驗(yàn)結(jié)果表明,分布溫度測(cè)量與準(zhǔn)分布溫度/應(yīng)變測(cè)量之間沒有干擾,分布溫度測(cè)量的溫度分辨率達(dá)到0.4℃,FBG準(zhǔn)分布式測(cè)量的溫度分辨率和動(dòng)態(tài)應(yīng)變分辨率分別達(dá)到0,08。C和64nε/(?),且可被FBG復(fù)用的光譜范圍超過50nnm。此外,針對(duì)油井下分布溫度與壓力同時(shí)測(cè)量的需求,設(shè)計(jì)了Raman/EFPI和Raman/EFPI/FBG融合測(cè)量系統(tǒng),并分別采用DTS和FBG溫度測(cè)量值對(duì)EFPI壓力測(cè)量進(jìn)行溫度補(bǔ)償,可分別實(shí)現(xiàn)5.3kPa和2.1kPa的壓強(qiáng)測(cè)量分辨率。該方案簡(jiǎn)化了系統(tǒng)結(jié)構(gòu),降低了系統(tǒng)成本,為光纖測(cè)井技術(shù)在油氣井開采中的推廣應(yīng)用奠定理論與實(shí)驗(yàn)基礎(chǔ)。
[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 鹵4.1 鈩，

本文編號(hào)：2323319