What are the functions of choke and kill manifold? Is it easy to use?
　　Choke and kill manifold is a kind of special well control manifold, which is composed of throttle valve, various valves, manifold and pressure gauge. It is used to control the discharge of annulus fluid and the back pressure of well. By squeezing clean water, killing fluid and cement slurry into the annulus, the purpose of killing well, waterproof and extinguishing fire can be achieved. It is an essential equipment for well control operation, especially for well killing operation.
　　Function of choke and kill manifold
　　The functions of the choke manifold are as follows:
　　(1) Through the throttling effect of the throttle valve, the killing operation is carried out, the contaminated killing fluid is replaced, the wellhead casing pressure and riser pressure are controlled at the same time, and the bottom hole pressure is restored through the killing fluid column to stop the overflow;
　　(2) Through the relief of throttle valve, the wellhead pressure is reduced to realize "soft shut in";
　　(3) Through a large amount of relief function of the blowout valve, the wellhead casing pressure is reduced and the wellhead BOP group is protected.

　　The functions of choke and kill manifold are as follows:
　　(1) When the wellhead is fully sealed with the full seal ram, the well pressure fluid is forced into the wellbore through the kill manifold to carry out the kill operation;
　　(2) In case of blowout, clean water is injected into wellhead through kill manifold to prevent combustion and fire;
　　(3) When the blowout is on fire, the fire extinguishing agent is injected into the wellbore through the kill manifold, which is helpful to extinguish the fire.
　　Classification of choke manifold
　　Choke manifold is usually divided into manual choke manifold and hydraulic choke manifold. The common throttling and standby throttling of manual throttling manifold are manual throttling. In addition to the casing pressure gauge, the five way pipe is also equipped with a vertical pressure gauge, and the pipe with the vertical pressure gauge is introduced by a self-supporting pipe. The common throttle valve of hydraulic throttle manifold is hydraulic throttle valve, whose opening is controlled by special hydraulic control box, and the standby throttle valve is still manual throttle valve.