Deepwater Conductor Pre-Installation for First TLWP in Brazil
A. Silvio, J.C. Ruiz, M.F. Pereira, InterMoor
This paper presents an EPCI project for pre-installation of 15 x 36” conductors, 60 m long, to be integrated to a TLWP in Papa Terra Field at Campos Basin, Rio de Janeiro, in 3,940 feet water depth, located 65 miles from the coast. Such field development required 15 conductors to be installed under TLWP’s footprint with accurate requirements for positioning, stick up and vertical inclination, all to avoid risers clashing during its 25 years production life. A patented installation method was chosen, which is comprised by a craned offshore construction vessel, an offshore installation barge and a deepwater subsea hydraulic hammer. To ensure installation within Client’s specification, 5 subsea templates containing 3 slots were designed to orientate conductors’ landing into the seabed. Template deployment was guided by an acoustic survey system measuring in real time the load’s position and orientation.
All conductors were transported to the field and side launched by the installation barge using the project-specific handling tool named “shuttle system”. The conductor’s weight was quickly transferred to the OCV’s active heave compensated crane, which was connected to a multi-purpose tool named “STS Head”, also project-specific. The penetration of each conductor occurred in three stages: (1) self-weight, (2) suction and (3) hammering. This EPCI project uniqueness is related to: (a) the first TLWP to be installed in Brazil; (b) patented method used to pre-install conductors; (c) shuttle system specifically designed for conductors’ side launching; and (d) STS Head.
The main objective of this method is to improve field development schedule saving rig drilling time. Successful project implementation definitively offers to Brazilian operators a field proven solution, since this technique is applicable for any type of conductor or subsea foundations, being used three times in Brazilian waters.