Flexible and Rigid Pipe Solutions in the Development of Ultra-Deepwater Fields

Abstract

The development of the offshore segment during the last three years was remarkably important for the oil industry due to some major achievements observed in the technical area, more specifically on the development of pipe solutions for ultra deepwater (UDW) applications. Brazil and Gulf of Mexico (GoM) have lately been the two main regions for application of proven pipe solutions in UDW. In Brazil, flexible pipes have been widely used in the development of UDW fields by Petrobras, while in the GoM, rigid pipelines and SCRs have been used for the majority of deepwater field developments. The main advances in flexible pipe technology are linked to the development of two major Petrobras fields located in the Campos Basin named Roncador and Marlim South. Technip-Coflexip has, through Technical Cooperation Agreements with Petrobras, designed, tested and installed flexible pipes, proving the fitness of this kind of product to UDW applications. The qualification of flexible risers for 1500m WD and flexible flowlines for 2000m WD are highlighted as being the main achievements. Extensive testing programs including, collapse, fatigue and offshore full scale tests have been put in place in order to simulate the design conditions to be seen by the pipes during installation and operation phases. The main design aspects in UDW like collapse, radial and lateral buckling of tensile armours, fatigue and thermal insulation will be covered in this paper and the current available technologies to tackle these issues will be presented. Similar design and qualification issues exist for rigid pipelines and risers (SCRs). The following three areas are specifically covered in this paper: collapse resistance of steel pipe; fatigue strength of plastically strained girth welds: and qualification of pipe-in-pipe thermal performance. These are some of the key areas of reeled pipe in deepwater applications that require successful project qualification. Technip-Coflexip has performed internal R&D programs on these areas as well as project specific qualifications. Both will be addressed by the paper.