The Performance of KH and KG Flexible Riser with Distributed Buoyancy Modules Configuration

Abstract

As a relatively new technology in the riser structure, Distributed Buoyancy Modules (DBM) are seldom to use on flexible risers in Indonesia Oil and Gas Fields which are dominated by brown fields. DBM have several advantages compared with conventional subsea structures such as Mid-Water Arches (MWA) in installation phase. DBM provides lower budget spending due to the shorter period and easier method in installation phase. The paper presents engineering design of DBM operation and installation in Kakap Field, Natuna Sea, Indonesia to replace the existing KH and KG Risers. Several cases was evaluated in this paper to perform the behaviour of risers using DBM. Based on the static analysis, the maximum effective tension for KH Riser and KG Riser are 100.7 KN and 83.4 KN respectively during their operation with allowable value of less than 1530 KN. Meanwhile, the minimum bending radius for the risers when they are being operated are above the allowable value of 3.926 m which are 6.6 m and 6.7 m for KH and KG Riser in turn. The analysis indicates the both of risers are safe to operate during their life period.

Geometric analysis of pontoon and mooring line towards hydrodynamic response

“…The displacement of the position of a floating building by a certain distance due to wave loads is called vessel offset (excursion) [20]. The amount of offset that occurs is related to the vessel's mooring line.…”