This type of steel pipe needs to face the pressure of nearly 40Mpa equivalent to about 400 atmospheres, the low temperature of the sea floor and the complex marine environment. Every trace of error and crack can cause serious consequences. The manufacturer carefully designs the chemical composition of the pipe and adds special elements in the production to ensure that the pipe has both strength and toughness; the processing technology is specially improved to ensure the ultra-high precision of the steel pipe size. Relevant results were recently submitted to experts from CNOOC Research Institute, China Classification Society Offshore Technology Center, CNOOC Shenzhen and Shanghai Branch for review and approval. The expert group reached an unanimous conclusion after in-depth analysis, arguing that the production strategy and technical route are reasonable, the product indicators meet the project requirements, and have the conditions for mass production.