Nope dead wrong again.
I worked in the oil fields three summers ago driving supper vac truck for a few months and spent loads of time on oil rigs doing cleanup work. and I can assure you if gas levels were that high alarms would be going off all over the place.
In fact everyone I saw who worked on the rigs had multigas clip on monitors they wore everywhere and I had one as well.
The other thing is oil rigs are designed to industrial hazardous location safety spec codes that require all lighting and electrical systems to be built to full explosion proof standards and are inspected regularly to make sure they meet those safety codes. Many of them even had cell phone bans in place and anyone even carrying a cell phone on a site would have it taken away and could not get it back until they left the site.
On top of all of that they also have minimum lighting standard codes they need to meet as well which means that they are very well lit to begin with.
In fact most are so well lit that if you are within two city blocks of a rig site you can work in the middle of the night without ever needing a flashlight.
The clunky open wire twisted pair power distribution design of the isotera systems would get them tossed in the trash as soon as the first inspector walked by one.
So once again I can assure you from personal experience that the isotera systems would not be used on oil rigs.