Integration of Advanced Material Components to Deepwater Platforms
Authors: Karayaka Metin 
Published: October 2008

Numerous riser, mooring, pipeline, subsea, and topside components made of polyester, titanium, glass/epoxy, and glass/carbon/epoxy materials are commercially available or in the process of qualification for offshore use. These advanced material components have potential to extend capabilities of existing platform concepts such as Semisubmersibles, TLPs, FPSOs and SPARs. Emerging field development concepts such as deepwater subsea processing and long tie-backs, new floating platform designs (variations of TLP and Spar concepts), new riser systems (submerged platforms, free standing riser towers, and buoyancy systems) may also benefit from the advanced materials components. This paper summarize technical and commercial issues in integration of advanced material components to offshore field development.

Introduction

As the offshore industry moves aggressively to pursue deeper water developments, composite materials are finding a wide range of new applications for both topside and subsea structures. The number and volume of composite material applications will continually increase provided that the composite industry responds to the unique challenges of the offshore industry. Offshore industry acceptance of these components depends on exploiting the potential of advanced materials to increase the platform performance and cost effectiveness, and to reduce technical risks compared to steel component counterparts. When favorable combinations of these factors exist, technological, economical, and regulatory barriers can be overcome. The relationship among risk, cost, and performance in commercial applications of advanced materials is illustrated in Figure 1.

Performance.

All commercially available and emerging advanced material components offer superior performance characteristics when compared to their steel counterparts. The performance advantages are typically combinations of lower weight, higher strength, higher fatigue resistance, higher durability, and enhanced corrosion resistance. Constituent properties, along with the design-to-fit characteristics of the advanced materials, are the main reasons for this increase in performance. The performance improvement can be at the component level, such as a corrosion resistant firewater pipe or a keel joint, or at the system integration level where the weight savings and superior performance of individual components allows potential cost and performance benefits in associated platform systems. Light weight composite TLP tendons and risers, for example, may allow significant downsizing of the TLP.

Figure 1. Advanced materials technology drivers for offshore applications (Available in full paper)

Cost.

Although advanced material components are typically more expensive than their steel counterparts, the added costs are often justified by improvements in component or system performance. For deepwater platforms, the cost benefit of advanced materials can be significant when evaluated at the system level. Weight savings in the risers, tendons, and mooring components will lead to more cost-effective floating platform designs.

Risk.

Offshore industry acceptance of advanced material components is directly related to operational risks. For low risk applications, such as certain topside components, it is easier to address regulatory concerns and to overcome the technical challenges of replacing steel components. For highrisk applications, such as moorings and risers, the regulatory requirements are more stringent, making already significant technical challenges even more difficult.

The three drivers (performance, cost, and risk) of offshore advanced materials technology are combined in Figure 1 to ge