Abstract
Flow-induced pulsations (FLIP) are pressure oscillations generated inside flexible pipes used in dry gas applications that can cause unacceptable vibration levels and eventually failure of equipment. Because of the design of inner layer of the flexible pipe, the carcass, the frequency of the pulsations is high, potentially leading to fatigue failures of adjacent structures in a relatively short time.
The paper will show the application of FLIP assessment and limit state design for typical flexible pipe usage in subsea gas production, enabling operation below the FLIP threshold level, as well as how the newly developed and qualified near-smoothbore anti-FLIP carcass allows for very high flow velocities. The paper will show how FLIP design challenges has been overcome in a typical gas field subsea production scenario and how the new anti-FLIP carcass has been fully qualified.