Well Control - Kick whilst tripping
If an overbalance existed prior to pulling out of hole, then the only reasons for the well to flow are:·swabbing;·failure to keep the hole full;·losses induced by surge pressures.
Early detection of kicks off bottom can be achieved by observing whether the hole is taking the proper amount of fluid during roundtrips. This can be achieved by pumping across the flowriser with the trip tank (also called possum belly) which will give an immediate indication of gains or losses. Trip tank fluid levels observed during roundtrips should be recorded . . .