RE:RE:RE:RE:Kawa Pay Zone?Investnowplease, You don't find swelling smectites that deep. They've undergone diagenisis and have been converted to non reactive, hard, brittle illites that deep. Over-pressured, spalling shale? Quite likely.
Regarding your H2S comment: The mud engineer would have run a Garret Gas Train at least twice a day to determine if there was H2S creeping into the mud and if yes then the mud engineer would have jacked up the alkalinity and added H2S scavenger to the mud. The companyman and OIM would have ordered special precautions on the drill floor where everybody would have been required to mask up if H2S in the air got over a certain concentration (10 ppm if memory serves). Plus they have H2S sensors at the shakers and other places. They don't mess around with H2S. It will drop you faster than a gunshot to the head. They don't rely on just the gas chromatograph either. H2S kills your sense of smell as well so you can't rely on human sensory perception either.
Regarding the p&a. They probably installed a retrievable cap in the well head. If they ever want to come back to the well, then they can re-enter it. So I'm not so sure that this is a permanent abandonment. Did they say that it was? Gotta read the NR again.