Method for producing gas cylinder pipe with diameter of phi610 to 720 for natural gas underground storage well

The invention provides a method for producing a gas cylinder pipe with the diameter of phi610 to 720 for a natural gas underground storage well, which comprises the following steps of: smelting steel according to the material chemical component requirement in the execution standard, and adding a phi400 continuously cast round billet into a continuous pipe rolling mill unit; performing mechanical cold centering on a cold centering machine; heating the centered pipe billet in an annular heating furnace, preserving heat, punching, and performing hot sizing; sawing the head and the tail, marking a furnace number and a pipe number, heating a steel pipe serving as a pipe billet, preserving heat, and performing rotary expanding and rolling; adding the pipe billet obtained by reeling into a walking beam type reheating furnace, normalizing on line, and sizing by using a sizing mill to obtain a finished steel pipe product; and making the finished product pass through a finishing area, and performing aftertreatment on the finished product. The method has the advantages that: the external diameter dimensional tolerance of the finished seamless steel pipe product obtained by the method throughcontrol can reach -/+1 percent D, wall thickness tolerance can be effectively controlled to be -12.5 percent to +15 percent S, and curvature can reach 1.2 percent L; and the gas cylinder pipe for thegas storage well, which is produced by the method, has high geometric dimensional accuracy and low cost, and internal and external surfaces meet the quality requirement.