On the exterior of the marine riser, two pipes are used for well control. What are they called?

• A. Flow Lines and Choke Lines
• B. Choke Lines and Kill Lines
• C. Kill Lines and Mud Lines
• D. Annulus Lines and Choke Lines

Answer: (B)

On the exterior of the marine riser, the two lines used for well control are the kill line and the choke line. The kill line provides a direct path to pump heavy kill mud down the well, raising the hydrostatic pressure to kill or control a kick. The choke line feeds fluids back to the surface through a choke manifold, where the flow can be throttled to maintain safe pressure and controlled circulation during well-control operations. This pairing is standard because you need both a way to inject kill fluid and a way to regulate the return flow; the other names refer to different parts or concepts not used in this exterior riser setup.