原油含水率测量的光学计量仪

油井含水率是油田开发过程中的一个重要指标。光纤传感器具有体积小、重量轻、抗干扰能力强、实时、高效、准确等优点,将其应用于石油测井,有利于提高勘探效率。介绍测井应用中原油含水率计量仪的结构,分析了光纤传感器对混合液体含水率测量的基本原理。激光在弯曲光纤中的传输效率随外界混合介质折射率的变化而改变,根据光纤输出光功率的大小可以测量外界混合介质的组成成分。通过数值模拟,给出了光纤传感器中光束强度随混合液体含水率的变化现象,计算得到混合液体中含水率测量结果。结果表明,光纤传感器计量仪能实现0%～100%含水量的连续测量。最后基于数值模拟结果讨论了系统设计中的注意事项。

Measurement System for Water Holdup in Crude Oil using Optical Sensors

Water holdup is important for exploitation of oil fields.Due to the advantages of optical fiber sensor such as small volume,light weight,anti-disturbance,real time,high-efficiency and accuracy,it can be applied in petrol well logging in order to improve logging efficiency.The configuration of optical measurement system for water holdup is described,and the application method of optical fiber sensors is analyzed for water and gas content measurement in well logging in this paper.The sensing principle is that laser intensity in optical fiber bend waveguide is changed with external refractive index,which is affected by the component parts of outside mixture medium.According to the measurement principle,it is simulated on the computer that laser intensity in optical fiber bend waveguide is changed with water holdup in crude oil.Results show that optical fiber sensor is suitable for the measurement of water holdup in crude oil when water content is widely changed in a large-scale range from 0% to 100%.Based on this analysis,some important issues are analyzed in designing the measurement system.