Limiting deformation of double walled rigid tube for use subsea comprises dividing annular space between tubes into zones, injecting hardenable composition into zones and sealing injection orifices

摘要

Limiting the deformation of a double walled rigid tube by having bulkheads divide the annular space between the tubes into zones, injecting a hardenable composition into the zones via an orifice in each zone and sealing the orifices. The zones are 0.5-5 m in length. The composition is injected after the tube before or after it is unwound from a spool. The composition hardens at ambient temperature and hardening is accelerated by passing the unwound tube through a heating zone.