Kallum Morland, Blaine Weller
Papers # 2012 Barcelona
An enhanced reinforced thermoplastic pipe for higher temperature (RTP-HT) applications has been introduced utilizing a high performance grade of PE material (Bimodal HDPE-RT) to cater to oil and gas pipelines that experience continuous service temperatures of up to 82°C (180°F).
The primary use of RTP-HT has been in the upstream oil and gas industry for a range of oil and gas gathering applications. RTP-HT offers cost-effectiveness, resistance to corrosion, joint reliability, rugged design and demonstrated efficiency of installation.
The objective of this paper is to demonstrate the design and performance verification approach of this innovative pipe product, particularly the compatibility of RTP-HT pipe in gas condensate containing high aromatic and cyclo-aliphatic hydrocarbons. An extensive test program, in addition to 10,000 hr regression hold testing, has been conducted to evaluate this innovative pipe. This test program includes thermal cycling, elevated temperature ageing, low temperature impact and rapid gas decompression testing. Testing was conducted in accordance with the requirements of API 15S. The test program to determine the chemical compatibility of RTP-HT consisted of exposing polymeric liner samples to highly aromatic and cyclo-aliphatic hydrocarbons at a maximum operating temperature of 82°C (180°F) and also with a 25°C (77°F) increase from the maximum operating temperature. The combined effects of temperature and aromatics were evaluated by mechanical property analysis of the saturated samples.
Similar tests were also conducted with pipe and field fitting samples. The results allowed for the determination of acceptable concentration levels of aromatic hydrocarbons at a variety of temperatures.