Corrosion Resisting Liners – The Results of an Investigation into Plastic Lining of Pipelines for Corrosive Hydrocarbon Service

摘要

While onshore oilfield experience has established that internalrnplastic liners sucessfully prevent corrosion of carbon steel piperntransporting water and hydrocarbon based fluids. The samernexperience has demonstrated that in case of multiphasernproduction service, with associated gas, plain plastic liners canrnhave a limited life.rnOne significant failure mode of plastic liners involves thernpermeation of (associated) gas through the plastic liner andrnaccumulation of that gas in the annulus between the liner andrnsteel host. This annular gas expands during depressurizationsrnof the bore leading to liner collapse. The use of vents onshorernhas proven, at best, partially successful in managing thisrnfailure mode.rnThe Corrosion Resistant Liners (COREL) Joint IndustryrnProject (JIP) has addressed methods for preventing annularrngas induced collapse.rnPhase I of the JIP was devoted to brainstorming potentialrntechnical solutions, the grooved liner and the perforated linerrnconcepts being taken forward. Phase II carried out deskrnstudies and small-scale tests to determine whether thesernsolutions were feasible. Phase III placed both solutions, eachrnapplied to Polyethylene (PE) and Polyamide-11 nylon (PA-rn11), in a dynamic test loop, simulating multiphase productionrnservice, at temperatures up to 80℃ and pressures up torn100bar, with regular pressure fluctuations over a 26-weekrnperiod.rnThe combined results of all this work demonstrate that therngrooved liner and the perforated liner concepts both preventrnliner collapse and mitigate corrosion, opening the way forrnwider application of plastic liners in production flowlinernapplications.