Page 186 - Well Control for Completions and Interventions

178 Well Control for Completions and Interventions

Figure 4.28 Inside blow out preventer (gray valve).

more than for open ended pipe, so small pit gains or losses become more
difficult to detect, moreover, reverse circulation is not possible.

4.11 MUD GAS SEPARATOR

Gas handling equipment is vital for the safe removal of the large
volume of gas that is often present following a kick. The mud gas separa-
tor, also called the gas buster or poor-boy degasser, is the first device
downstream of the choke during a well control operation. It is used fol-
lowing a kick to separate kick gas from the brine or mud as it is circulated
out of the well, allowing mud or brine that was in the well to be recov-
ered and reused; an important consideration when pit space is limited.
The mud gas separator is not part of the normal circulation system, and is
only normally used for well control.
A mud gas separator is basically a gravity separation tank. Mud or
brine flowing from the choke enters the vessel and drops down through
several baffle plates. This causes the light gas to break out from the liquids
and flow up into the vent line, where it is vented to atmosphere through
the derrick line (offshore), or directed away from the rig, usually to the