PROCESS AND ASSEMBLY FOR INSTALLING SERVICE LINES USING A J. GUIDE TUBE

摘要

PCT No. PCT/US80/01066 Sec. 371 Date Mar. 5, 1982 Sec. 102(e) Date Mar. 5, 1982 PCT Filed Aug. 21, 1980 PCT Pub. No. WO82/00697 PCT Pub. Date Mar. 4, 1982.A method and apparatus for installing a pipeline riser (90) through a J-tube (40) at a spud can-founded, compliant, offshore platform (20) are disclosed. The J-tube is mounted on the platform above the maximum expected mudline (28). An upper longitudinal section (44) of the J-tube passes through guide rings (46) on the platform while a lower longitudinal section (48) is maintained free of the platform. After platform settlement, the J-tube is lowered to an elevation near the actual mudline (30). During riser installation through the J-tube, a lower end (54) of the J-tube is restrained from lateral movement by a latch (70) attached to the platform. Before production operations, the lower end is released from the latch so that flexibility of the J-tube accommodates movement of the platform.