It seems that most are assuming that the reason for the gas kick is high pressure gas (eg CH4), but could it be due to a higher than expected concentration of CO2?
eg could there have been a reaction to change CH4 + 2H2O + S into CO2 + 2H2 + H2S. Wouldn't this cause a pressure rise within an enclosure?
I would welcome comments. I still hold, but have not yet bet the house on this.
925mug.