现有气测录井技术所使用的烃类气体来源主要是使用电动脱气器分离钻井液中的烃类组分,将其混入空气送入气相色谱检测,主要得到的是C₁—C₅气态烃组分。这种方式一方面受钻井液的影响,另一方面由于空气含量的不确定性,只能定性地评价油气显示。半透膜对烃类组分具有一定的分离选择性,可以直接插入钻井液进行油气分离,能得到气态和常温呈液态的烃类组分,相对于电动脱气器具有受影响因素少,能定量评价油气含量的优点。因此,在技术气测录井中,为了提供定量烃类气体来源,通过对半透膜气体分离技术的研究,研制了适合要求的半透膜以及基于半透膜的油气分离装置。对这种分离装置的响应时间、分离效率、衰减检测、C₁—C₈(包括苯、甲苯)组分响应等性能的试验结果证明,其适用于钻井现场的油气检测,扩展了油气检测内容,丰富了油气评价信息。

In the current mud logging gas measurement technology, the hydrocarbon gas mainly comes from the electric degasser, which churns up the drilling fluid to separate the hydrocarbon gas, and to get C₁—C₅ gaseous hydrocarbon components. The content of the hydrocarbon gas detected by this way is, on the one hand, affected by the drilling fluid, and on the other hand, due to the uncertainty of the air content, the oil and gas display is only evaluated qualitatively. The semi-permeable membrane can separate selectively the hydrocarbon components, and can be directly inserted into the drilling fluid to separate the oil and gas, and thus the hydrocarbon components of the gas and liquid can be obtained at a normal temperature. This method enjoys a number of advantages, such as, it is less affected by the drilling fluid, and it may provide a quantitative evaluation of the oil and gas content. Therefore, in order to evaluate quantitatively the hydrocarbon gas sources in the mud logging gas measurement technology, a proper semi-permeable membrane and the related apparatus for the oil and gas separation are developed. The parameters, such as the response time, the degassing efficiency, the gas attenuation, and the response characteristic of C₁—C₈ (including benzene and toluene) are studied. It is shown that the oil and gas can be detected while drilling at the well site, with a richer information about the content of the hydrocarbon detection and the hydrocarbon reservoir evaluation.