NEW CROSSLINKED POLYETHYLENE PIPES WITH HIGH THERMAL STABILITY AND LOW PERMEATION FOR PETROLEUM ENGINEERING
NEW CROSSLINKED POLYETHYLENE PIPES WITH HIGH THERMAL STABILITY AND LOW PERMEATION FOR PETROLEUM ENGINEERING
Gisbert Rieß, Katrin Berger, Anna Kaltenegger-Uray, Florian Arbeiter
# 2021 Amsterdam
The effect of electron-beam and silane crosslink of polyethylene on the resulting permeation characteristics was investigated. Polyethylene sheets were processed and crosslinked by irradiation with high energy electrons and by grafting and subsequent hydrolysis of organosilanes during a reactive extrusion process. The formation of a network structure was characterized by sol/gel analysis. It was demonstrated that the crosslink density increase with the irradiation energy and has an optimum with 4 phr silane. The permeation properties were assessed by a gravimetric method. It was demonstrated that – as a result of the crosslink process – the permeation of low molecular weight hydrocarbon such as n-octane through polyethylene is reduced with respect to the crosslink density. Additionally, to bypass limitations of the gravimetric method a new measuring method based on gas-chromatography-mass-spectroscopy (GC-MS) technique was developed. The main advantages of the newly developed system were demonstrated by test measurements of filled PE pipes. The comparison of the calculated permeation rates of tested hydrocarbons using both measuring methods showed a good accordance of the results. With this new GC-MS method pipes can also tested in the field.
