When oil comes up in to the shakers it comes up with drilling mud and that alters the composition." So it wouldn't be a reliable sample, it also implies that the zone is of a higher pressure then expected." The way it was described it had a nice sheen to it implying a medium grade oil at the least."
... no AF it may not imply a higher-pressure [BHP], unless associated with gains ... though it's maybe a good sign.
... AF then perhaps you can explain how all other 'samples' were taken on A-1 Well ? note that I'm referring to a 'surface sample' not a PVT, BHS or Dead Oil sample and clearly may not be [DH] representative ... were was the ~15-API A-1 Well 'surface sample' taken from ?
... while your at it perhaps give Le-Cone a quick lesson on why a rig has a shaker deck and rig pumps !
From my understanding the well was drilled overweight and hence no oil initially made its way into the well bore." Over time pressures with in the well after being plugged normalised and that has allowed live oil to enter up the well." This does imply a pressurised oil column exists in Marti-5 with oil at least in the medium quality"
... yeah real hard guess the well was OB ... [MPD package rigged-up?!]
... you are talking about a well plugged back in the 1980's right? ... so maybe 30 years ... over that timeline any well may have swapped-out [no I'm not going into detail on that] with accumulation at surface. Valves [gate/seals] may degrade over time, leaks may occur ... if it was a HP well, they you may have much more than a 'leak' ! ... [well integrity issues]
... every shut-in [inc.P&A] wellhead is in theory maybe building-up pressure infinitely ... even moon phases may affect pressure
(20min delay)