地层条件下油气混合气安全氧含量实验研究

Experimental study on safe oxygen content of oil-gas mixture under reservoir conditions

为了确定地层高温高压环境下油气混合气的安全氧含量,避免在采油过程中形成可燃性混合气体引发燃烧或者爆炸事故,保证注空气采油工艺过程的安全性,设计了1种测试地层高温高压环境下油气混合气体安全氧含量的实验装置;通过对采油现场井筒内的气体进行取样分析,选取一定组分的混合气体,在理论分析的基础上,对混合气体分别在1,5,10 MPa和40,120℃条件下的安全氧含量进行了实验研究,并将实验结果与理论分析结果进行了比较分析。研究结果表明:随着温度和压力的升高,安全氧含量逐渐降低;在地层高温高压环境下所测得的安全氧含量要远低于常温常压下的理论估算值;在10 MPa,120℃时达到8.27%,很大程度上增加了采油工艺过程的危险性。

In order to determine the safe oxygen content of oil-gas mixture under the reservoir conditions of high temperature and high pressure environment,avoid the combustion or explosion accidents caused by the combustible mixture in the course of oil recovery,and ensure the safety of air injection oil recovery process,an experimental device was designed to test the safe oxygen content of oil-gas mixture under the reservoir conditions of high temperature and high pressure environment.The mixture with certain components was selected by sampling and analyzing the gas in the well bore on the site of oil recovery.On the basis of theoretical analysis,the safe oxygen contents of mixture at 1 MPa,5 MPa,10 MPa and 40℃,120℃were studied experimentally,and the experimental results were compared with those of theoretical analysis.The results showed that with the increase of temperature and pressure,the safe oxygen content decreased gradually.The safe oxygen content measured under the reservoir conditions of high temperature and high pressure environment was much lower than the theoretically estimated value under normal temperature and pressure.It could reach 8.27%at 10 MPa and 120℃,which greatly increased the risk of oil recovery process.