Study On Gas Sensing Detection Techniaues Of Oil And Gas Wells

With the development of modern industrial technology, the security of petroleum andnatural gas exploration as well as environmental pollution and so on a series of problemsbecome the focus of attention. The oil, natural gas exploitation, industrial production and dailylife produce poisonous and harmful gas, of which high sensitive detection becomes urgent.Compared with traditional sensors, optical fiber sensors has incomparable advantages such ashigh sensitivity, fast response, large dynamic range, anti-disturbance of electromagnetism,high insulation, passivity, flameproof explosion-proof, for remote telemetry, small volume,flexible elastic deflection and so on. It is suitable for applications in harsh and hazardousenvironments, therefore, received widely attention. The spectrum absorptive optical fiber gassensors for detection of poisonous and harmful gas effect is good, therefore, the research ofwhich has been seriously regarded at home and abroad.In this paper, the spectrum absorption type optic fiber gas sensors are studied, designingand improving the structure of the gas sensors, designing the sensing signal demodulationscheme. The hardware circuit processes are detailed. Meanwhile, the sensitive material Agadsorbing H₂S molecule spectrum characteristics are discussed in the paper. The silver fiberBragg grating sensor and characteristics of silver plating fiber grating sensor adsorbing H₂Sgas are studied in experiment. The results show that fiber Bragg grating sensor silver plated isfeasible.This paper is based on Beer-Lambert law, using H₂S gas as a main target gas, and usingC2H2gas as an auxiliary gas. Gas spectral changes in the transmission type gas chamber arestudied, measuring the change of light intensity of gas absorption peak, to achieve the goal ofdetecting gas concentration. The main content of the research as follows:Based on principle of gas molecular absorption spectrum, the absorption lines and linewidth of gaseous molecule are introduced simply, also spectral absorption detection principleand measuring method of optical fiber gas sensor are introduced simply. According to theabove theoretical analysises, to detect gas sensors is designed. Using the sensor to C2H2, H₂Sgas detection is studied. Weak signal processing is an important part of optical fiber sensor system. In this paper,gas absorption processing producing weak photoelectric signal sensing signal demodulationscheme is designed, and reasonable weak signal detection circuit is designed. Finally tohydrogen sulfide as the detection of target gases, carried out to study the concentration.According to the experimental data, performance of the system is analyzed.