Vibration Analysis of an Oil Production Platform

Abstract

The present paper investigated the dynamic behaviour of an oil production platform made of steel and located in Santos basin (Merluza field), São Paulo, Brazil. The structural model consists of two steel decks with a total area of 1915 m2 (upper deck: 445 m2 and lower deck: 1470 m2), supported by piles. Mechanical equipments were located on the steel decks of the structural model, related to electrical generators and compressors. The proposed computational model, developed for the steel platform dynamic analysis, adopted the usual mesh refinement techniques present in finite element method simulations implemented in the GTSTRUDL program. In the computational model, floor steel girders and columns were represented by three-dimensional beam elements, where flexural and torsion effects are considered. The steel decks were represented by shell finite elements. The representation of the soil was based on the Winkler’s Theory. A numerical analysis was made, in order to assess the dynamic behaviour of the deck structure when subjected to actions coming from the electrical generators and compressors. Based on the peak acceleration values, obtained on the structure steadystate response, it was possible to evaluate the structural model performance in terms of human comfort, maximum tolerances of the mechanical equipment and vibration serviceability limit states of the structural system, based on the design code recommendations.