分析了煤层气井液面在测量中使用的传统方法可能遇到的问题, 提出了光纤非本征型珐珀干涉仪(EFPI)用于测量煤层气井液面的发展方向。针对煤层气井设计了光纤EFPI传感系统, 并模拟煤层气井液面给出测量方案, 准确地测出液面位置, 解决了煤层气井液面的测量难题, 测量系统中传感器光学腔长变化的相对误差为1.48%, 测量精度1μm, 相比传统的电学测量方法, 更加安全有效。

The problems possibly occurred in the coal bed methane(CBM) well measurement are analyzed. An extrinsic Fabry Perot(F-P) interferometer(EFPI) is used as a new direction of liquid surface measurement in coal bed methane well. A liquid surface measuring system on the EFPI is developed to fundamentally solve the difficult problems of the accurate level in the coal bed methane well.The relative error of optical cavity length is 1.48% and resolution is 1μm in the measuring system, which is obviously more effective than the traditional measuring technologies.