Installation of Long Span Boat Landing on Float Over Platforms - A Case Study

Fixed offshore platforms are normally provided with landing platforms that enable berthing of supply vessels, crew boats etc. These landing platforms or ‘Boat landings’ are energy absorption structures provided on substructures (jackets) of offshore platforms. Their purpose is to facilitate personnel access from vessel to platforms for performing various tasks including manning the platform, its maintenance etc. Vessel also approach the platforms for providing supplies in case of a manned platform and for providing bunkers, spares etc. As such, boat landing is an integral part of offshore platform and its design and installation becomes equally important. They are preferably located at leeward direction as far as practical, to avoid accidental vessel drift into the platform. For smaller standalone offshore platforms installed with Heavy Lift Crane Vessels, boat landing is installed after the jacket is piled to seabed. Since sequence of installation of boat landing is prior to that of Topside, such installations are straightforward and without obstructions from the Topside. For the bigger accommodation, production, process platforms located in super-complex (or standalone) with topsides installed by float over method, boat landings sometimes are in the wide float over barge slots. In such cases, installation of boat landing becomes very critical due to the post installation after the Topside and associated obstructions from the Topside. This is similar or more critical than a boat landing removal / refurbishment activity carried for a brownfield project. This paper explores the challenges and associated steps adopted to execute the safe installation of these critical structures underneath a newly installed Topside. This case study details the installation of ∼300mt boat landings onto recently installed Greenfield platforms in Arabian Gulf using efficient rigging, suiting the EPC Contractors’ crane assets.

Planning of an offshore platform maintenance campaign

Within the scope of industrial megaprojects, such as a large-scale maintenance campaign for an oil platform, planning for tasks that will be executed in highly dynamic environments – defined by variability, uncertainty, and unforeseen events – is a challenging job. The Ergonomic Work Analysis (EWA) by the maintenance planning technicians showed that, despite the different strategies in use, there are limits in the possibility of predicting a future context. Thus, planning is a collective process of reducing uncertainty, but it requires instrumentalization of the players involved therewith.

Evaluation of Neural Architecture Search Approaches for Offshore Platform Offset Prediction

This paper proposes a solution based on Multi-Layer Perceptron (MLP) to predict the offset of the center of gravity of an offshore platform. It also performs a comparative study with three optimization algorithms – Random Search, Simulated Annealing, and Bayesian Optimization (BO) – to find the best MLP architecture. Although BO obtained the best architecture in the shortest time, ablation studies developed in this paper with hyperparameters of the optimization process showed that the result is sensitive to them and deserves attention in the Neural Architecture Search process.

Success Story of First Malaysia Flare Tips Decommissioning in Sarawak Offshore Field Platform

The project was for part production enhancement project which to cater for brownfield & greenfield project. To cater to the production (oil) increment for the brownfield project, the existing flare tips and separation system need to be upgraded with higher capacity. The inclusive project was upgrading existing. Part of the scope was decommissioning the existing flare tip and associated system, e.g., ignition panel and ignition pipe. The project will decommission the current flare tips and replaced it with new higher capacity flare tips with Low Pressure (LP) & High Pressure (HP) connection. The existing flare panel was a single-type ignition system. The existing flare tip had LP & HP tip with 8″ inch size; the weight for both tip was estimated at 300 kg. The concept selection was discussed on the suitable method to lifting down the decommissioning flare tip at the offshore platform. There were 2 suitable techniques selected at the initial of the concept selection. One was lifting down the decommissioning flare tip directly from flare boom to vessel. Another method was manual rigging of the flare tips from the flare boom to the lower deck. After several discussions and workshops, it was decided to proceed with manual rigging of the decommissioning flare tip to the safe deck area. The removal of the decommissioning flare tip was performed during turnaround. The total days for the overall activity of the decommissioning & installation of the new flare tip was 3 days, 2 days ahead from planned duration 5 days.

Study on Slamming Pressure Characteristics of Platform under Freak Wave

Freak waves have great peak energy, short duration, great contingency, and strong nonlinear characteristics, and can cause severe damage to ships and marine structures. In this study, numerical simulations in conjunction with experimental tests are applied to study air gap response and wave slamming loads of a semi-submersible offshore platform under a freak wave. A three-dimensional wave tank, which is created based on the computational fluid dynamics (CFD) method, is applied to study the hydrodynamic responses of a semi-submersible platform. The numerical model of the tank and offshore platform system are checked according to the experimental results. A typical freak wave is modelled in numerical wave tanks by the linear superposition method, and its significant wave height is 13.03 m. It is found that the freak wave is closely associated with the wave slamming. The appearance of the freak wave gives rise to a negative air, gap which appears on the side of the back wave surface at the bottom of the deck box, and considerable slamming pressure is generated. Furthermore, the wave run up at the junction of the column and the buoyancy tank is also seen due to the freak wave.