Oil sands hydro-transport requires pipes to be corrosion and erosion resistant. To achieve this requirement, appropriate coating can be applied to the inside of metallic pipes. Polymeric liners may provide a cost effective solution; however, such systems are prone to catastrophic liner collapse caused by pressurized gases and fluids trapped at the liner/pipe interface. To resolve this problem, a novel filament-wound fibre reinforced composite pipe with an intrinsically bonded polymeric internal liner capable of venting trapped volatiles is presented. In addition, this paper addresses an appropriate joining technique for inevitable pipe connections.
The growing worldwide demand for hydrocarbon resources has resulted in accelerated development of unconventional and hard-to-exploit oil deposits. This includes oil sands deposits in north-eastern Alberta where substantial amounts of bitumen-rich material are being removed in open-pit mining operations. In many cases this material is moved from the mine and processing plants by pipeline hydrotransport. In this process, granular material is transported as aqueous slurry. After bitumen extraction, so-called tailings are transported by pipeline from processing facilities to sites where separation of solids and water occurs. The hydro-transport of massive amounts of slurry mixture causes significant metal loss in conventional metallic pipelines, which results in short replacement cycles and considerable cost 1,2. The present paper describes a novel polymeric pipe structure that aims at mitigating these problems while simultaneously offering cost and operational advantages.
Current pipe structures for slurry hydro-transport are typically made from low carbon steel. It has been observed that fast moving solids in the slurry flow can cause considerable metal loss of the inner pipe wall. The aqueous and aerated slurry flow causes accelerated pipe erosion by providing for a corrosive environment 3. Under the influence of gravity, particulate matter in the slurry causes damage along the bottom inside half of the pipes. Hence some mining operators have implemented the practice of periodically rotating pipelines to maximize lifespan. Nevertheless, pipe erosion remains a serious problem, and alternative pipe structures or materials are sought to provide more economical operation. It was shown that steel pipe with a hardened inner surface may mitigate pipe erosion 3. Alternatively, it is possible to clad steel pipe with corrosion and erosion resistant coatings such as ceramics or metal matrix composites 4. Although being viable solutions cladding steel piping requires more complex processing and installation procedures which results in increased initial cost for pipeline structures. Certain polymers were found to also offer excellent wear characteristics 5,6. Hence, providing conventional steel pipe with an erosion and corrosion resistant polymer liner promises to be an economical means for increasing service life. However, this solution may render pipes susceptible to liner collapse 7. The cause of this failure mode is the diffusive permeability of polymers to certain fluids. Consequently, the pipe/liner interface may be subject to corrosive deterioration causing imperfect bonding between the two constituents. Under such conditions modest amounts of volatile species may accumulate in the pipe/liner annulus. Being contained in the impermeable steel pipe, fluids accumulated along the liner/pipe interface are subject to pressurization during normal operating conditions. Several studies 7-10 have shown that pressuri
