Underwater flowline connector

Abstract

The underwater flowline connector includes a cable puller, cable cutter, alignment device, and flowline bundle for remotely pulling and aligning an outboard hub with a subsea inboard hub disposed on an underwater unit. The cable puller is located atop the underwater unit and includes a plurality of hydraulic cable grippers alternatingly engaging and releasing the pull-in cable connected to the flowline bundle to pull the bundle with outboard hub to the underwater unit. Pulling by the cable puller cntinues until the flowline bundle has reached the porch of the underwater unit. During its final ascent along a ramp of the porch, the flowline bundle rights itself because of a self-righting moment on the bundle caused by attaching the cable above the center of gravity of the flowline bundle. The flowline bundle is attached to the alignment device using a universal joint. The alignment device has central hydraulic extension cylinder mounted on the universal joint to engage and lock the flowline bundle. Another hydraulic cylinder, operating on a rack and pin gear assembly, is used for rotating the flowline bundle, in either direction for vertical alignment on the unit. The lateral extension cylinder retracts the universal joint causing the backplate of the flowline bundle to abut the aligment device, thus aligning the faces of the inboard and the outboard hubs parallel to one another. The lateral extension cylinder on the alignment device is also used for final lateral alignment of the outboard hub with the inboard hub. Once pull-in and alignment is completed, a hydraulic cable cutter mounted beneath the cable puller is actuated to sever the flowline pulling cable.