含硫天然气井井喷失控15分钟H_2S扩散数值模拟

Numerical simulation of H_2S diffusion for sour natural gas well after uncontrolled blowout for 15 minutes

根据油气井现场实际条件,建立了数值计算的物理与几何模型。主要考虑环境风速和井喷气口初始喷出速度两个主要因素,对井喷后15min H2S浓度分布进行分析。研究结果表明:2m/s以上的风速可以使H2S扩散形成一个沿风向偏转下压的类似椭圆的区域,并且下压的程度随风速增大而增大;气体喷出初速度一定时,H2S的扩散区域随着风速的增大而增大,但是近地面类椭圆较高浓度区域则呈现先增大后减小的趋势;当环境风速一定时,H2S的扩散区域随着喷口初速度的增加而增大;在较高的喷出速度条件下,H2S扩散会出现涡流,扩散至远处地面后还会出现"反弹"的现象。

According to the actual conditions of oil and gas well,physical and geometric model by numerical simulation are established.To analyze H2S concentration distribution after uncontrolled blowout for 15 min,the environmental wind speed and the initial blowout jet speed are mainly considered.The results show that the wind speed above 2 m/s can form a similar elliptical area along the direction of the wind deflection due to the H2S diffusion,and the press extent increases with the wind speed raising;when the initial gas jet velocity is certain,the spread area of H2S increases with the wind speed raising,but the approximate-oval high concentration area is presented increases at first then decreases trend;When the environmental wind speed is certain,the H2S diffusion area will increase with the increasing of initial gas jet speed;In the higher jet speed conditions,H2S diffusion will appear eddy current,then 'bounce' phenomenon will also appear after H2S spreading to the distant ground.