气体钻井返出气体检测方法研究

气体钻井技术具有提速增效、保护储层的良好效果，应用前景广阔。但在钻进过程中，若不能及时发现储层已被揭开并调整钻井工艺，就很可能因大量地层气体溢出及地层高压突然释放而导致井壁失稳、气体燃爆等井下复杂情况，也不利于储层的发现和评价；同时地层可燃有毒气体泄漏会引起地面人员及装备等安全事故，增加气体钻井风险。这就要求气体钻井必须建立一套新的气测体系。这一体系须响应快、灵敏度高，能适应气体钻井高钻速、高注入量、低迟到时间等应用条件，为气体钻井安全提供保障。为此，分析了实施气体钻井排砂管线返出气体在线检测的意义、目前气体钻井气测存在的问题．以及目前工业应用中多种常用气体检测方法的适用范围及响应特征，结合气体钻井现场应用条件，提出了改进方向，对完善气体钻井返出气体检测技术具有一定的指导作用。

Study on return gas detection methods for gas drilling

Gas drilling indicates a faw）rable effect in enhancing the penetration rate, improving economic performance and protecting reservoir, and it has a wide application prospect. But in the process of drilling, if we can not timely find that the reservoir has been opened and can not adjust the drilling procedures in time, it＇s likely to lead to a series of borehole problems, such as wellbore instability bums and so on because of the effusion of massive formation gas and sudden release of high pressure of formation. It is unfavorable to the find and evaluation of reservoir. At the same lime, leakage of burnable toxic gas will result in the safe accidents for surface personnel and device and will increase the risk of gas drilling. This requires that gas drilling musl build up a set of new gas detection system. The system must be rapid response, high sensitivily, and must adapt the application conditions of high drilling speed, high injeetion rate, low lag time, which provides a safe guarantee for gas drilling. Therefore, this paper points out the current problems of gas logging, analyzes the signifieances of on-line gas detection in the blooey line and the response eharaeteristies of the common gas detection methods in industrial application in detail. Combined with the application needs and conditions of gas drilling, new improvements have been put forward, which has a guide action to the improvement of return gas detection of gas drilling.