高温高压下N_(2)和CO_(2)对CH_(4)/C_(2)H_(6)/C_(3)H_(8)混合气抑爆效果研究

Study on the Explosion Suppression Effect of N_(2)and CO_(2)on CH_(4)/C_(2)H_(6)/C_(3)H_(8)Mixtures at High Temperature and High Pressure

油田伴生气经常会发生燃爆事故,为提升采油过程的安全性,需研究N_(2)与CO_(2)在井筒高温高压条件下的抑爆效果.目前对于高温高压条件下固定可燃气体积分数,不同体积分数N_(2)和CO_(2)对爆炸特性影响的研究较少.对40℃,初始压力0.5、1.0、2.0 MPa,不同N_(2)和CO_(2)体积分数下CH_(4)/C_(2)H_(6)/C_(3)H_(8)混合气到达最大爆炸超压的时间、最大爆炸超压和爆燃指数KG进行了相关研究,分析了不同初始压力和2种惰性气体对爆炸特性参数的影响.试验结果表明:不同初始压力下N_(2)和CO_(2)各自的惰化机理相同;CO_(2)的惰化效果优于N_(2)且存在最优点,该点之前CO_(2)的惰化效果与N_(2)相比优势逐渐增强,由化学作用占主导地位,该点之后化学作用已达到最大效果,因此CO_(2)的惰化效果虽仍强于N_(2),优势却逐渐减小.

In order to improve the safety of oil production,the explosion suppression effect of N_(2)and CO_(2)under the condition of high temperature and high pressure in the wellbore needs to be studied.At present,there are few studies on the effect of different volume fractions of N_(2)and CO_(2)on the explosion characteristics of a fixed ratio of combustible gas to oxygen under high temperature and high pressure conditions.At 40℃,the initial pressure of 0.5,1.0 and 2.0 MPa,the time for CH_(4)/C_(2)H_(6)/C_(3)H_(8)mixture to reach the maximum explosion overpressure,the maximum explosion overpressure and the deflagration index KG under different N_(2)and CO_(2)volume fractions were studied and analyzed.The effects of different initial pressures and two types of inert gases on the explosion characteristic parameters were investigated.The test results show that the inerting mechanisms of N_(2)and CO_(2)are the same under different initial pressures;the inerting effect of CO_(2)is better than that of N_(2)and has the optimal point.Before this point,the inerting effect of CO_(2)is gradually stronger than that of N_(2),and the chemical effect is dominant,after this point the chemical action reaches its maximum effect,so the inerting effect of CO_(2)is still stronger than that of N_(2),but the advantage is gradually reduced.