"Wet insulation pipe use supplanted pipe-in-pipe insulation as the most used way to meet flowline performance demands over the past five years. Glass microsphere technology has fostered development of flowline insulation alternatives that reduce thermal conductivity and make deepwater hydrocarbon recovery feasible.
Expanding deepwater E&P in recent years has prompted major technology investments in flowline design to control thermal losses in long subsea tiebacks and in wet tree completions. There are subsea assets where it is economically viable to expand peripherally to recover additional reserves at reach-out distances of 50 km (31 mi) or more. Extended subsea pipe lengths and a trend to deeper and hotter drilling conditions have prompted a search for flowline insulation technologies with increased mechanical strength and reduced heat transfer."