Directional stability of the torpedo anchor pile during its installation

Abstract

The so-called torpedo anchoring system is a novel and yet already intensively field-proven by Petrobras (the Brazilian oil company) offshore, Brazil. It is a pile with a specific elongated form that is buried in the sea bottom to hold mooring lines that are connected to floating production units. This is so even for very deep water (typically 1800 m). The methodology of installation of the torpedo pile so far consists of a vertical launching, starting with the torpedo above and close (typically 100 m) to the sea bottom. This installation path then occurs from the pile at the starting position with zero velocity until it reaches the bottom. During this installation, the pile travels almost freely, only dragging the mooring line. It is obvious that the object has to have a minimum directional stability to arrive vertically at the bottom. The pile becomes useless when it gets a vertical angle that is outside certain limits (typically three degrees). The present article addresses the directional stability of the torpedo pile during the installation.

An innovative booster-assisted dynamically installed fish anchor and its installation characteristics considering the action of ocean currents

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Ensaios de campo de penetração auxiliada por jatos de água de modelos de estacas torpedo em solo granular

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