Patent ID: 8413722

Claim:
A method for removing a fluid influx from a subsea drilling wellbore, the wellbore drilled using a pump to return drilling fluid from the wellbore to the sea surface, the method comprising: observing the fluid influx; continuing to pump drilling fluid through the drill string and the return pump until the fluid influx reaches the wellhead, the return pumping performed at a rate such that a flow into the wellbore substantially equals a flow out of the wellbore; hydraulically isolating an intake to the return pump; diverting flow out of the wellbore to a choke line; operating the choke so that the flow into the wellbore substantially equals a flow out of the wellbore; diverting flow out of the wellbore back to the intake of the return pump when an end of the influx reaches the wellhead; pumping a less dense fluid down a kill line from the surface to proximate a bottom end thereof and thereto proximate a bottom end of the choke line; and displacing influx fluid from the choke line.