Jin Bin Hai News(Reporter Zhang Boyan, Correspondent Zhang Yaju, Shaodong, Jiang Chang) Recently, the deep-water subsea oil production tree feeding device - the deep-water located pipe string, independently designed by the new area enterprise CNOOC Development Engineering Technology Company, has obtained two national invention patents.These two patents are "an underwater tubing hanger assisted detachment mechanism and operation method" and "a sealed shear ball valve for deep water"...