天然气钻井井口安全距离研究分析

Study and Analysis on Safety Distance of Natural Gas Wells

分析天然气钻井井场可能发生的事故类型及事故的破坏程度,选择适合的事故后果模型,对天然气井井喷失控后可能发生的蒸气云爆炸及硫化氢扩散的后果进行量化分析,根据超压-冲量准则、热剂量准则和硫化氢扩散行为规律,计算出爆炸波、爆炸火球及硫化氢扩散的危害范围。笔者建立了天然气钻井井口安全距离的计算模型,并提出一种确定安全距离的方法。通过计算给出不同无阻流量、不同硫化氢体积含量的20种条件下的天然气钻井井口安全距离,并应用该模型对某含硫气井井口安全距离进行了计算。实例表明,该方法具备实用性,值得在天然气井选址规划中推广和使用。

The accident categories and accident severity in the process of drilling natural gas well are analyzed. By selecting appropriate accident result model, the result caused by vapor cloud explosion and hydrogen sulfide diffusion that may occur due to losing control of well blowout, is quantitatively analyzed. Then, according to overpressure-impulse criterion, heat quantity criterion and hydrogen sulfide diffusion regulation, the damaging ranges caused by explosion wave, explosion fire sphere and hydrogen sulfide diffusion are respectively calculated out. At the same time, a model for calculating the safety distance of natural gas wells is provided, and a method to determinate the safety distance is presented. Besides, 20 kinds of safety distance of natural gas wells with different open flow quantity and different concentrations of hydrogen sulfide are provided through calculation. Finally, an applied, example is demonstrated with this model, it practically shows that this method is worth popularizing and applying to the plan and site selection of natural gas wells.