Splash zone lowering analysis of a large subsea spool piece. (March 2020)

• Record Type: Journal Article
• Authors: Li, Lin; Parra, Carlos; Zhu, Xinying; Ong, Muk Chen
• Is Part Of: Marine structures. Volume 70(2020)
• Publication Date: 2020-03
• Subjects: Large spool -- Splash zone -- Time-domain simulations -- Allowable sea states -- Operability; Naval architecture -- Periodicals; Offshore structures -- Periodicals; Architecture navale -- Périodiques; Structures offshore -- Périodiques; Naval architecture; Offshore structures; Periodicals; 620.4162
• DOI: 10.1016/j.marstruc.2019.102664
• Languages: English
• ISSNs: 0951-8339

Abstract

Abstract: Lifting operation though the wave splash zone is challenging. Careful numerical analysis in the design phase is needed to minimize associated risks. This study addresses numerical modeling and analysis of the splash zone lowering of a large subsea spool. A typical offshore construction vessel is used for the operation. The objective is to compare the effects from different numerical methods and parameters on the allowable sea states and the operability. These methods and parameters include wave short-crestedness, shielding effects from the vessel, wave direction and wave seed number. A coupled numerical model of the spool-vessel system is established in SIMO program, which is a simulation tool for marine operations. Slamming and submergence-dependent loads on the spool during the transient lowering process are calculated. A large number of time-domain simulations has been performed to derive the allowable sea states. The operational criteria for assessment of the sea states include slack sling, snap loads in wires and clearance between spool and the vessel. Operability analysis of the operation at one reference site in the Barent Sea is established using 50-year hindcast data. The influences from different methods on the allowable sea states and the operability are compared and discussed in detail. Highlights: Numerical modeling and analysis of the splash zone lowering of a large subsea spool is presented. Sensitivity studies on wave short-crestedness, shielding effects, wave direction and wave seed number are performed. The effects from the above parameters on the allowable sea states are compared. The operability at one reference site in the Barent Sea is established and compared using different methods.