Lifting Operations for Subsea Installations Using Small Construction Vessels and Active Heave Compensation Systems: A Simulation Approach

Abstract

Sub-sea installation operations require a high level of accuracy and control in order to avoid misalignment and possible collisions between modules on the sea bed. To reduce costs, smaller and lighter construction vessels are now performing these operations. The most critical parts of the operation are lift-off from the deck, passing through the splash zone, and landing sensitive equipment on the sea bed. The hazards are: high dynamic loads, resonance effects, and slack line snap. Therefore, in this study, modeling and simulation are applied to optimize design parameters and develop operational procedures for each operation to reduce risk of failure. Further, the same models can be used in operator simulator training. Modeling and simulation of interactive multi body systems is a rather complex task, involving the vessel as a moving platform, lifting equipment such as cranes and winches, guiding devices, lifting cables and payload behavior in air, all while partly to fully submerged. It is a multi-physics problem involving hydrodynamics, mechanics, hydraulics, electronics, and control systems. This paper describes an approach to link the different models to simulate the operations including interactions between the sub-systems. The paper focuses on the modeling approach used to connect the various dynamic systems into the complete operating system. The work is in its initial phase, and some of the sub-systems models are not complete. The models are described in this paper and will be included in future work. Some initial operational examples are included, to show how the models work together.

Design of a novel installation device for a subsea production system

“…A simple single-freedom, mass-spring-damper model can illustrate the system: the mass is the object being lowered, and the spring is the lowering line [21]. The steel clump chain is much shorter and heavier than the nylon rope, and thus the weightbalancing chain and the deployment vessel can be simplified as a single-freedom vibration system in the Z-axis direction [22], and the mass of the weight-balancing chain is concentrated at the lower end.…”

A Computer-Automated Design Tool For Intelligent Virtual Prototyping Of Offshore Cranes

“…In addition, for the last few years, our colleagues in the Mechatronics Laboratory at AAUC have published several papers relating to modelling, simulation and visualisation of offshore cranes and installations. (e.g., Sanfilippo, Hildre, AEsøy, Zhang and Pedersen, 2013;Sanfilippo, Hatledal, Schaathun, Pettersen and Zhang, 2013;Sanfilippo et al, 2014;Chu, Sanfilippo, AEsøy and Zhang, 2014;Chu, AEsøy, Zhang and Bunes, 2014;Halse et al, 2014;Hatledal et al, 2015).…”

“…As noted by Halse et al (2014), advanced marine operations such as subsea installations consist of multiple subsystems that must be collectively controlled in a precise manner and typically involves controlling a crane and winch mounted on a vessel operating in a dynamic, uncertain environment affected by wind, waves, currents, shape and size of payload, and more. Modeling and simulation of such interactive multibody systems is a complex task that involves hydrodynamics, mechanics, hydraulics, electronics, and control systems (Halse et al, 2014).…”