Na Kika - Host Construction for Record Water Depth Platform
Authors: Fairburn Michael E. , Gage Jason H. , Kenney John J. , Knoll David A. , Lindsay Mark S. , Miller Brian H. 
Published: October 2008

The Na Kika Development is located in water depths ranging from 5,800' to 7,000' in the US Gulf of Mexico. The project, a joint effort by Shell and BP, is a subsea development of five independent fields tied back to a centrally located, permanently moored floating development and production host facility.

The construction of the Na Kika Host met many challenges potentially facing future projects, including: accelerated schedule, constricting Contractor base, overseas logistics, 33,000st onshore integration and transport, coordinating interfaces with other project activities and handing over the facility to a different operating company. The Na Kika host was installed in summer 2003 and is currently the deepest permanently moored oil and gas production facility in the world. Accelerated schedules and the construction of larger and more complete packages are expected to be commonplace challenges in the future. This paper presents the project's experience in contracting, fabricating, transporting, and commissioning the host facility.

Introduction

The contracting strategy considered worldwide contracting options utilizing a combination of lump sum and "unit rate" approaches to allow competitive contractor selection prior to design completion. Na Kika developed an efficient division of Contractor responsibilities including the procurement of long lead and critical equipment where Shell's control and relationship with vendors provided additional value. Shell, as the general contractor, employed quality processes to assure delivery of the desired product. Management of change and scope phasing was critical in optimizing schedule performance in the face of uncertainty and difficulties. Hyundai's Guinness World Record Superlift allowed construction of the host on land with improved lower elevation access, independence from drydocks and heavy lift cranes, and greater schedule flexibility. Loadout and dry transport of the completed Na Kika host pushed the envelope allowing the delivery of a more complete package from foreign sites. Na Kika controlled Commissioning provided the flexibility to adjust for schedule pressures in fabrication. A secondary construction site in the Gulf of Mexico was utilized to provide flexibility in managing construction and commissioning work scope to optimize the overall construction schedule. Underlying HSE focus was consistent throughout, yielding good results and investments in future performance.

Field Description

The Na Kika development comprises five separate fields:Kepler, Ariel, Herschel, Fourier and East Anstey, that would have been uneconomic if not developed as one system. The fields are roughly spread out West to East, with the two furthest wells being roughly 25 miles apart. In addition, the Coulomb field, South East of the Na Kika host, is tied back with a flowline that is 27 miles in length. The fields were drilled as early as 1986. In 1996 a systems selection effort was started to first determine the technical feasibility of systems in water depths over 6000 ft and then develop a commercially viable solution.

Host Description

The Na Kika Host (shown as a 3D drafting model in Figure 1) is composed of a 4 column, ring-pontooned hull supporting 4 modular deck sections. This Floating Development System (FDS) is moored in a water depth of 6350' by a 16-leg semi-taut mooring system. The semisubmersible deck structure is composed of four structurally independent modules.