Lucius Offshore Installation of Flowlines, Risers and Topsides

Abstract This paper provides an overview of the design, fabrication and installation of Anadarko's Lucius Development flowlines, risers and topsides including all ancillary lifts required to fully complete the installation of the Lucius Spar. The production flowlines, risers and associated structures were fabricated and installed by Heerema Marine Contractors US, Inc. utilizing the new build vessel DCV Aegir. At the time of contract execution the vessel was still under development and new vessel procedures as well as project installation procedures were required to perform the installation safely and within schedule. The export risers and flowlines were designed and fabricated by Technip USA, Inc. and installed using the Deep Blue reel installation vessel. The export risers were pulled in utilizing a custom built 1,000-ton capacity chain jack system designed, fabricated and installed by Versabar, Inc., The topsides installation was performed by Heerema Marine Contractors US Inc. utilizing the heavy lift vessel DCV Thialf for the 10,000-ton topsides lift and the heavy lift vessel DCV Balder for the ancillary lifts. Some of the unique challenges addressed in this paper include some "firsts" which include the design and qualification of titanium stress joints on the export risers, the design and qualification of a diverless close in spool system as well as the design and qualification of a diverless pull head required to hang off the export risers. This paper also addresses the design and offshore installation of a 1,000-ton chain jack system which was designed late in the project life to install the export risers after the main topsides was installed. Additional firsts included the use of pile based riser base pipeline end manifolds which were designed to allow for a tight subsea architecture and sustain extensive bottom tension loads.