Development of In-Line PLETs for Tupi Pilot Project:Challenges and Lessons Learned

Abstract NOTE: The TUPI field name has changed to LULA field; therefore hereafter we will refer to it by the current name LULA. This paper will describe the challenges, experience and lessons learned on the development of the In-Line PLETs, for the Lula Pilot Project. The project used the first of its kind In-Line PLET and installation methodologies for Brazil's record ultra-deepwater field Lula. The Lula Pilot Gas Export Pipeline is an 18?? diameter×218 Km Pipeline connecting FPSO Cidade de Angra dos Reis to Mexilhão Platform (PMXL-1). The subsea equipment used on the project were the following: Deepwater PLEM, In-Line PLET, In-Line Wye, Shallow Water PLEM and Jumper Connectors. There were many new challenges on the project. The first was to design an In-Line PLET and In-Line Wye that were small enough to fit inside the tensioner of an S-lay vessel and strong enough to withstand the installation loads of Lula's 2145 meters water depth. The In-Line PLET and In-Line Wye both have identical configurations that consist of Stress Joints, Pipe-in-Pipe Joints, Swivels, Wye, Ball Valve and Tie-in Hub. But the In-Line PLET's Wye straight brach leg was designed into a Dead Leg to be used as an anchor point to tie-in the additional 320 feet of pipe and laying head needed to set down the In-Line PLET. Addition items included Pipe-in-Pipe Joints, Stress Joints and Swivel. These were used to reduce the stress on the pipeline and equipment during installation. Another challenge was coordinating the project with the customer and the installation contractor. In addition to the multiple customers, there were multiple manufacturing sites for the equipment, including Houston, Aberdeen, Milan, Paris, Victoria, and Rio. Design Qualification Testing was completed on the 18?? Intergal Collet Connector and a 10?? Annular MCV Connector. The 18?? Collet Connector was used to tie-in the rigid jumper and the 10?? Annular MCV Connector was used for the Flexible Jumper tie-in. Finally, this paper will describe the successful deployment and installation of the In-Line PLETs, which helped to launch Brazil's record setting Pre-Salt Discovery Lula. Introduction A well know subsea layout for Pipeline termination is the use of PLETs connected by Rigid Jumpers to PLEMs. PLEMs can be placed anywhere along the pipeline to allow a future connection to the main Pipeline. An alternative to avoid PLEMs in the middle of the Pipeline and therefore reduce the installation time is the use of a system that can be welded to the Pipeline and deployed in line with the Pipeline, or, In-line systems.