应用于石油测井的新型光纤干涉流量计的研究

提出一种新型非浸入式测量光纤干涉流量计,当流体流过管壁时可由湍流产生振动,紧密缠绕在油管外壁的光纤能够感应振动信息,通过管壁振动频率特性范围内确定出的由湍流诱发管壁振动加速度脉动值标准方差与平均流量的量化关系,即可求解出相应的流量。目前实验完成了5～60m3/h的较大流量量程的监测,测量精度为±5%FS,为下一步进行小流量量程监测提供良好的基础。

Design for a new type of flowmeter based on fiber optic interferometer for oil well logging

In the oil well logging,fluid flow is an extremely important parameter which determines the transmission characteristics of the oil production.Real-time monitoring of fluid flow parameter provides a scientific basis for the oil and gas optimization exploration and the increase of reservoir recovery.A new type of non-intrusive flowmeter based on fiber optic interferometer is proposed.The pipe′s vibration is induced by turbulent flow and the fiber optic sensors wrapped closely around the outside wall of pipe are used to sense the information of vibration.The frequency characteristics of the pipe′s vibration signals are found,and the relationship between the standard deviation of pipe wall′s vibration induced by fully developed turbulence and the mean flow rate is determined.The experiment has accomplished flow monitoring whose range is from 5 m3/h to 60 m3/h,and the measurement accuracy is±5%FS.It provides a good basis for further monitoring of the small flow.