随钻检测用微型红外甲烷气体传感器

Miniature infrared methane gas sensor for measurement while drilling

为了满足石油勘探过程钻井液中甲烷气体同步检测分析的需要,实现甲烷气体随钻检测的目标,本文设计了一种可集成于钻具内的随钻检测用微型红外甲烷气体传感器。首先利用Hitran数据库对甲烷气体的红外吸收峰进行了对比分析,确定了探测器滤光片的中心波长;然后利用光学仿真软件TacePro对腔体内的光线传播方向进行了光线追迹分析,并对到达探测器2个接收面的光强分布进行了模拟分析,确定了光学腔体设计的合理性,随后根据红外气体传感器的工作原理设计了相应的工作电路。测试结果表明该传感器对甲烷气体的检测精度在常温下优于0.5%F.S.,在120℃下优于0.8%F.S.;常温下实现了对甲烷饱和水溶液中脱出的微量甲烷气体的检测,可以满足甲烷气体随钻检测的需要,在石油钻井行业的随钻检气体测领域具有广阔的应用前景。

In order to meet the needs of synchronous analysis of methane gas in drilling fluid and realize the goal of methane gas measurement while drilling（MWD） , a miniature infrared methane gas sensor for MWD is designed. First, the infrared absorption peak of methane gas was compared and analyzed with Hitran database to determine the center wavelength of the detector filter. Then the optical simulation software TacePro was used to analyze the light propagation direction of the cavity and the light intensity distribution of the two receiving surfaces of the detector, which can deter- mine the rationality of the optical cavity design. Finally, the corresponding working circuit is designed according to the working principle of infrared gas sensor. Experimental resuhs indicate that the detection accuracy of the sensor is better than O. 5% F. S. at room temperature and better than 0. 8% F. S. at 120 ℃. The detection of trace methane gas in the saturated aqueous solution of methane can be realized at room temperature, which can meet the needs of methane gas measurement while drilling . This sensor has a wide application prospect in the field of oil driling.