Versatility in Answering the Challenge of Deepwater Field Developments

Abstract

Abstract The paper will address the application of a versatile asset in the execution of a multifaceted deepwater installation project. An asset equipped such as the Borealis supporting heavylift, S-lay, J-lay and Flex-lay can allow the project to design installation scenarios which address very specific permanent equipment qualifications while promoting cost effective installation and schedule advantages. Most deepwater projects include several permanent components which require intense engineering focus and special capabilities to facilitate installation. The complexities of the installation exposes the offshore operation to risks and opens opportunities for innovation in design and methodology of installation as mitigation measures. The combination of the thorough onshore installation engineering, the asset capabilities, and the flexibility of installation methodologies available can allow the project to take the full benefits surrounding complex issues. The paper builds case studies in which the application of the various installation methodologies could provide significant flexibility benefits in the execution of a deepwater project. The case studies will review the technical considerations related to vessel capabilities and the challenges of several project scenarios. Focus will be direct towards advantages derived from specific operations such as:–Installation Sequence: S-lay to J-lay–Installation Sequence: J-lay to S-lay–Installation by J-lay and S-lay with pipeline structures–Complex existing infrastructure scenario–Full Field development scenario Brief method statements and risk/opportunity reviews are provided for each case study. The Borealis has the capabilities required to address challenges presented in the execution of a multifaceted deepwater installation project. With heavylift capabilities of over 5,000Te, including extended subsea reach, the asset is well suited for surface and subsurface lifts. The S-lay capability allows for higher production rates and economical installations over longer pipeline lengths. Capabilities in J-lay makes the vessel versatile in the installation of SCRs, ultra-deepwater pipelines significant Inline Structures/PLETs/PLEMs and subsea manifolds. The vessel will be prepared for installation of flexibles using a 500 T flexlay tower. Introduction Differing from shallow water field developments, deepwater field developments have specific technical challenges both in design as well as installation of the offshore infrastructure. In recent years the boundaries of technical capabilities in design and installation techniques have expanded and field developments are moving into ever deeper water depths, further away from existing infrastructure. Examples of existing deepwater developments are: Chevron Tahiti, Anadarko Independence Hub / Trail development, Chevron Blind Faith, Chevron Jack & St. Malo, etc. etc. Future developments could include: Hess Tubular Bells, Exxon Hadrian, Hess Pony, Anadarko Lucius, etc.