摘要
岩石中气体化学组成的分析具有重要意义。载气保护下的岩石脱气,过程比较复杂;高真空下岩石脱气的气相色谱分析报道较少,一般不能测量气体的总量;真空脱气质谱法对于分子量相近的气体,很难进行测量。针对上述问题,本文研制了高真空岩石样品脱气分析装置,该装置真空度<10-4Pa,空白样品压强<0.1 Pa,N2含量测量精度为0.63%,标准温压下最少可测样品量<1 mm3。将其与带脉冲放电检测器的气相色谱仪联用,实现了岩石脱气及其微升量级气体化学组成的高灵敏气相色谱分析。利用本系统分析了五大连池火山岩、松辽盆地储层岩石和四川盆地页岩样品中释放的气体,结果表明:相比以往的实验装置和方法,该系统能够直接测量岩石脱出气体的总量,分段加热脱气分析样品用量更少,气体组成分析灵敏度更高,检测的主要成分是岩石脱气常见的成分,针对性较强。
It is important to determine the chemical composition of gases trapped in rocks. The technique of using carrier gas and chemical analysis to release and collect gases is very time- consuming. There is little reported about Gas Chromatography analysis of rock degassing under high vacuum, and the total amount of gases are not commonly measured. It is difficult to analyze gases with similar molecular weights by Mass Spectrometer and because of these problems, a high vacuum rock sample degassing device has been developed. The vacuum of the device is 〈 10_4 Pa. The blank sample pressure is 〈 0. 1 Pa, the accuracy for N2 in the air is 0. 6 3 % , and the minimum measurable quantity is 〈 1 mm3 at standard temperature and pressure. The high vacuum device is coupled with a Gas Chromatography with a pulsed discharge detector, which gives a high sensitive gas chromatographic analysis of the chemical composition of gases in rocks. The gas released from Wudalianchi volcanic rocks in theSongliao Basin reservoirs and shale samples from the Sichuan basin have been analyzed using this system. The results show that the total amount of gas released from the rock can be directly measured. Less sample weight isneeded during stage heating, and gas composition analysis is more sensitive compared withdevice and method. The analyzed main component targeted is the common component in gas-released rock.
出处
《岩矿测试》
CSCD
北大核心
2017年第3期222-230,共9页
Rock and Mineral Analysis
基金
国家自然科学基金资助项目(41473062)
