Patent ID: 9109419
Filing Date: 2015-08-18
Classification: E21B

Abstract:
1. A system for maneuvering a plug in and out of a tubing hanger that is disposed in a vertical bore of the subsea wellhead assembly, the vertical bore having a vertical axis, the system comprising: a housing selectively lowered subsea and coupled with the subsea wellhead assembly, and that comprises a lower end with an opening; a chamber in the housing intersecting the opening, the chamber having a vertical wall adapted to be coaxial with the axis when the housing is coupled with the subsea wellhead assembly; a tractor selectively deployed along the vertical axis from within the chamber of the housing into the vertical bore of the subsea wellhead assembly and that comprises crawler members that extend radially outward from an axis of the tractor and into rolling contact against the vertical wall of the chamber for moving the tractor into and out of the vertical bore of the subsea wellhead assembly, and a motor that drives the crawler members; a reel mounted on the housing; a control cable spooled on the reel that has an end attached to the tractor and is in selective communication with a remotely operated vehicle (ROV) deployed subsea via a control hot stab on the reel; an end effector mounted to the tractor and selectively coupled with the plug, so that when the tractor is deployed from within the housing and located in the vertical bore of the subsea wellhead assembly, the end effector handles deploying the plug into the tubing hanger; and wherein the control hot stab on the reel enables the ROV to control the tractor and the end effector.