METHOD FOR EXTENDING THE USEABLE LIFE OF A POLYAMIDE PIPE LINER DURING USE IN A WATER-OIL-GAS ENVIRONMENT

摘要

Polyamide liners used in sub sea and over ground transport operations, such as nylon (11), are handled in a way which increases the rate of chain recombination relative to the competing process of chain scission. This enhances and increased the useable life of the polyamide liner by effectively reducing its rate of aging. This can be accomplished by incorporating a chain extender or desiccant into the polyamide liner, incorporating hydrophobic moieties or hydrophobic polymers into the polyamide liner, or by providing a sheath which is less permeable to water at the inner surface of the polyamide liner. Rejuvenation of the polyamide liner can also be achieved by heat treatment of the polyamide liner by hot air, hot oil or gas, or other hot liquids that are at a temperature above 1000 °C. Rejuvenation may be enhanced by including a chain extender or desiccant to a hot oil, gas, or other liquid that is exposed to the polyamide liner.