Have any morfe info on the geology or are you unable to share that?
high connection gas HPHT well example, on land, Indonesia drilling in the
transition zone, where every time pumps were off we had a 40-60% bottoms up,
mud loggers gas reading, supported by observing gas breaking out at the header
box. So as an engineer, if we reverse engineer the 'bubbles' breaking out, i.e.
using simple PVT calcs to bottom hole conditions, we conclude ml vs litres
entering well. Note: A very small volume i.e. less than 50ml entering into
these wells should in theory result in gas expansion and gas cut mud at
In our case there was no (0) gas cutting, just bubbles, coming from a HPHT source, the well was not flowing, finger print, return volumes were the same.
Contractor was adamant he was increasing mud weight and I was adamant we were not. After a time out for safety, a few more pumps off, bottoms up where I insisted on a pumps off-swab test, to convince drillers etc, there was no imminent danger downhole, we drilled to TD with same mud weight, had no issues and 40-60% pumps off and connection gas readings (for whatever reason.) that actually reduced and faded away after a few days.
Latent causes as to why, how this happened, Im not sure and we are still trying today to figure out what and why these readings result at surface! In conclusion it's a lot of things and quite complex! However stick to the basic and real indicators where in combination these should affirm when mud wt increase is needed.