Method and Apparatus for Drilling Multiple Subsea Wells From an Offshore Platform at a Single Site

摘要

A floating, offshore drilling and/or production platform is equipped with a rail-mounted transport system that can be positioned at a plurality of selected positions over the well bay of the vessel. The transport system can move a drilling riser with a drilling riser tensioner system and a blowout preventer from one drilling location to another without removing them from the well bay of the vessel. Using the transport system, the drilling riser is lifted just clear of a first well head and positioned over an adjacent, second well head using guidelines. The transport system may then move the upper end of the drilling riser (together with its attached tensioner and BOP) to a second drilling location. A dummy wellhead may be provided on the seafloor in order to secure the lower end of the drilling riser without removing it from the sea while production risers are being installed.

主权项

1. A tension leg platform comprising:
a deck structure of a drilling deck for supporting topsides equipment and a production deck equipped with a well bay; an upper surface on the production deck and an undersurface on the production deck and a through opening in the production deck from the upper surface to the undersurface; the production deck further comprising a drilling riser assembly that comprises a drilling tensioning joint and a drilling riser tensioner assembly, the drilling riser assembly being supported in a drilling riser transfer assembly, wherein the driller riser assembly comprises a transporter adapted for translational movement within the through opening along a length of the well bay, the production deck is situated below the drilling deck in the deck structure, and a position of the transporter is held side-to-side by fixed rails forming a part of the deck structure.