INFLUX All this talk of gas influx has caused me some gas reflux!!.....but I think I have an answer.
Consider drilling and drilled background gas is steady. From there, drilling finds some porosity and the drilled gas naturally increases as larger rock pores are now opened to release the gas from rock, overpressured or not. To this degree, this can be called influx since the newly drilled gas is actually an influx into the previously drilled hole and current mud gas readings. It is still drilled gas. I'll say that the news release telling of gas influx for the drilling break was accurate in it's interpretation but not to be confused with an influx from the sandstone formation itself. That form of influx would be a gas kick into the well bore and evidently that did not happen.
In the same scenario, a drilling break now opens up long sections of porosity and larger rock pores containing higher gas volumes under pressure and compressed, and at triple the normal penetration rate so you can see how very large volumes of drilled gas is liberated from the rock and released into the mud in the wellbore and because of the high penetration rate as the drilling continues. It's easy to see how this looks to someone without the experience to have the foresight as to what can happen in a drilling break that goes on for nearly an hour. When the gas chromatograph showed the increased level of gas, I can see how some stuff could hit the fan. Someones idea to increase mud weight was their first line of defence and they may have gone overboard on that idea. This leads into the idea of correct drilling practices so a flow check after the drilling break should be conducted. With a well flow, immediately shut in and record pressures. No flow, drill ahead but at a controlled rate with steady but reduced weight on bit for control. Under certain conditions, if formation pressures are high enough with the mud column close to a balanced condition with the formation pressure, the gas cut mud from increased pore pressures at a high penetration rate can fluff up the mud to the degree that effective hydrostatic pressures of the mud column can become underbalanced to the formation pressure and a kick can be induced from the very high levels of drilled gas alone, even though the mud weight is enough to contain the formation pressures in it's own right. In this case the gas cut mud can be circulated out with the well shut in and circulating through the choke and routing the mud through the degasser. With the gas cut mud cleaned, drilling could resume with the same mud weight. ....just some food for thought