Thermoplastic Composite Pipes: A Reliable Cost-Effective Solution for Pre-salt

Abstract

Thermoplastic Composite Pipe (TCP) has a solid wall construction constituted from a single polymer material with embedded (melt-fused) fibre reinforcements. It is a disruptive technology where all the advantages for ultra-deep water developments come together: high strength, light weight, corrosion free, low CAPEX, etc. TCP is therefore one of the most promising solutions to overcome the recent failures found on pre-salt fields related to corrosion under high concentrations of H2S and CO2. However, introducing a new technology on very challenging applications such as deep water production risers, requires careful consideration and mitigation of all technical and project execution risks. This paper starts presenting a historical review of some of the new technologies applied offshore Brazil over the last 20 years making a parallel with the increasing acceptance of Thermoplastic Composite Pipe in the Brazilian market. Following the historical review, TCP technology is presented and strategy to enable free hanging catenary systems for ultra-deep water environments discussed. The basis of the study is a typical offshore Brazil pre-salt field and feasibility of 6" and 8" free hanging TCP risers were assessed. Study was performed in close cooperation with a major operator and an installation contractor in Brazil. Global, installation and local analyses of the TCP Riser system have shown the feasibility of installation as well as operations in a free hanging catenary configuration throughout the 30 years' service life. In 2017, this pre-FEED study was used as basis for a FMECA (Failure mode, Effects and Criticality Analysis). The FMECA exercise was carried out together with a third-party certification body and two major Oil & Gas companies very active in Brazil. A detailed business case study was performed in order to quantify the potential CAPEX savings that TCP technology can bring compared to the low lazy wave systems currently installed in pre-salt fields, offshore Brazil. Result is that if TCP is adopted as primary technology for Risers&Flowlines, significant savings are expected. Savings comes both from pipe and ancillary's procurement costs since TCP technology enables free hanging catenary configuration, avoiding purchase of expensive buoyancy modules. The outcome of this work lead to a qualification program currently being sponsored by one major operator active in Brazil. Technology Roadmap was established in phases being the ultimate goal the qualification of pre-salt 8.0in production lines. Reasons for adopting this qualification strategy is presented. The qualification is driven by DNV-ST-F-119, a dedicated standard for TCP design and qualification.