When tubing heated by hot formation fluids contacts colder fluids entrapped in the annulus, the result is fluid heating and pressure buildup. Proper well design is critical in subsea wells.
Vacuum insulated tubing (VIT) has been used successfully to mitigate the potentially harmful effects of annular pressure buildup (APB). In a recent deepwater installation, the subject well had lost alternate APB mitigation capability through a series of events. VIT was then chosen as the only viable technology.