高温高压下N2和CO2对CH4/C2H6/C3H8混合气抑爆效果研究

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N₂与CO₂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N₂和CO₂对爆炸特性影响的研究较少. 对40 °C，初始压力0.5、1.0、2.0 MPa，不同N₂和CO₂体积分数下CH₄/C₂H₆/C₃H₈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K_G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N₂和CO₂各自的惰化机理相同；CO₂的惰化效果优于N₂且存在最优点，该点之前CO₂的惰化效果与N₂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CO₂的惰化效果虽仍强于N₂，优势却逐渐减小. 

Study on the Explosion Suppression Effect of N2 and CO2 on CH4/C2H6/C3H8 Mixtures at High Temperature and High Pressure

In order to improve the safety of oil production, the explosion suppression effect of N₂ and CO₂ 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 N₂ and CO₂ on the explosion characteristics of a fixed ratio of combustible gas to oxygen under high temperature and high pressure conditions. At 40 °C, the initial pressure of 0.5, 1.0 and 2.0 MPa, the time for CH₄/C₂H₆/C₃H₈ mixture to reach the maximum explosion overpressure, the maximum explosion overpressure and the deflagration index K_G under different N₂ and CO₂ 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 N₂ and CO₂ are the same under different initial pressures; the inerting effect of CO₂ is better than that of N₂ and has the optimal point. Before this point, the inerting effect of CO₂ is gradually stronger than that of N₂, and the chemical effect is dominant, after this point the chemical action reaches its maximum effect, so the inerting effect of CO₂ is still stronger than that of N₂, but the advantage is gradually reduced.