Installation of the World's First Subsea Thermoplastic Composite Flowline for Hydrocarbon Service

Abstract The Thermoplastic Composite Pipe (TCP) has been established for a number of years as a viable alternative to steel and flexible pipe in subsea applications, with various intervention type of applications building track record in the field. After the successful installation of a Thermoplastic Composite Pipe for permanent methanol injection on Chevron's high-pressure Alder field in the North Sea in September 2016, Airborne Oil & Gas moved forward with the installation of a flowline for a full well stream application. The selection of a TCP Flowline ensures a CAPEX reduction as it is manufactured in long continuous length up to 6000 meter and reeled on lightweight transport /installation reels. This allows for reel-lay or surface tow installation with a low-cost installation spread, contrary to steel pipeline requiring slow lay-barges. Furthermore, the TCP flowline can be terminated on the platform and pulled through the I or J tube without the end-fitting, allowing for small and light I or J tubes. The TCP Flowline can be installed in a single pass, optionally with a weight coating to achieve on-bottom-stability and immediate burial with for example a jet trencher if required. This single vessel installation results in the lowest material and installation cost for TCP Flowline compared to the alternatives. Besides the CAPEX reduction, the selection of TCP flowlines ensures a significant OPEX reduction. Integrity management and corrosion prevention in particular have significant impact on operational cost. This is the case for new developments that more often see increasingly challenging environments with H2S, CO2, MIC etc, but also for existing operations that face unplanned shut-downs and repair cost caused by corrosion. The fully bonded TCP Flowline has significant advantages. The TCP does not corrode, has a smooth bore featuring low pressure drop, is collapse resistant to large water depth and combines pressure and tensile strengths with spoolability. The unique and specific properties of TCP make it a cost effective choice for a variety of different applications, from shallow water flowlines, to flexible high pressure jumper spools and deepwater risers.