What is the use of choke and kill manifold? How does it work?

　　What is the use of choke and kill manifold? How does it work? I'd like to give you a brief introduction.
　　1. Purpose
　　Choke and kill manifold is the necessary equipment to control kick and implement pressure control technology of oil and gas well. When the blowout preventer is closed, the choke and kill manifold uses the opening and closing of the throttle valve to control a certain casing pressure to maintain the bottom hole pressure slightly higher than the formation pressure. The choke and kill manifold prevents the formation fluid from further flowing into the well. In addition, when the choke and kill manifold is shut in, the choke manifold can be used for pressure relief to achieve soft shut in. When the choke and kill manifold reaches a certain limit, the choke and kill manifold is used for blowout to protect the wellhead.

　　What is the use of choke and kill manifold? How does it work?
　　2. Composition and structure
　　The choke manifold is composed of throttle valve, gate valve, pipeline, pipe fittings, pressure gauge, etc.
　　3. How it works
　　When the pressure in the well increases, the fluid in the well can be released to control the casing pressure by opening and closing the throttle valve (including manual adjustable, hydraulic and fixed) on the choke manifold. When the casing pressure is very high, it can be vented directly through the gate valve.