gas is brought to the surface the controlled rate of gas could flow through the riser boost line if the annular preventer is closed during a well control event in the main borehole small amounts of gas in the riser 108 can be mitigated with a riser gas handler below the slip joint and or with a diverter at surface which can give sufficient back pressure to control the flowrate should the gas surface it may do so rapidly and at a high rate with little warning without early detection of the gas if there is gas in the riser 108 and a significant amount of gas in the main wellbore simultaneous riser and well killing is performed in one embodiment this is a complex procedure and can split the attention of the operations personnel leading to oversight or error when done manually automation of the riser gas handling reduces such a risk by focusing attention on well established primary well control techniques for the main wellbore in a process controlled by the icis 204 international association of drilling contractors iadc well control procedures for deep water recommend that personnel be minimized on the rig floor when there is gas in the riser due to the severity of the risk methane gas detection and rig automation is another way of ensuring minimum risk of exposure of rig personnel to hazardous situations a number of variations and modifications of the disclosed embodiments can also.