The petroleum which drills for oil ballasting-up method of the riser tube for oil extraction and under the petroleum production system null seabed which

摘要

PROBLEM TO BE SOLVED: To decrease tensions to a minimum which act to the upper and lower end portions of oil lifting riser pipes.;SOLUTION: The buoyancy acting to a lower half portion of the riser pipe 1 is dispersed to the first section except an upper portion of the lower half portion and the second section except an upper portion of an upper half portion of the riser pipe 1.;COPYRIGHT: (C)2004,JPO