FPSO and TLWP Interacting at a Reduced Distance for Dry Tree Completion System

Abstract

Nowadays, an offshore industry challenge is developing a floating system with production, storage and offloading capabilities together with a dry tree system reducing costs and maintenance. A solution could be two offshore units working at the same area. The system consists of a unit with dry completion, like a well head platform with drilling and workover facilities, and other capable to produce the oil and gas, and storage them. A better option is to have both units coupled making them work as one. By doing this, it could be reduced the radius of the mooring line footprint and the risk of clashing between the lines and shuttle tankers. The dimensions of the unit with the dry tree could be decreased because some facilities could be allocated at the large unit with storage capacity. The main goal of this paper is show the viability of this innovative system composed by two offshore units. A Tension Leg Wellhead Platform (TLWP) and a Floating Production Storage and Offloading (FPSO) coupled by synthetic ropes and non-symmetrical mooring system. Some comparisons were done between the numerical results from Numerical Offshore Tank (TPN) and physical tests carried out in NMRI (National Maritime Research Institute - JAPAN). The model scale of 1:100 and the numerical model was set up with similar main properties and equivalent lines stiffness. The models were exposed to extreme wave conditions for some incidences. Besides that, regular wave and current analyses were generated as well.