This paper presents the knowledge applied in the development of a device to monitor the trajectory of the VLA type anchor into marine soil in very deep water. The main difficulty of VLA embedment operation is to assess its performance into mud once the final positioning is crucial for the correct functioning of the anchor. Attached to the anchor, the tracker device, by using a PC104 computer technology, is capable of measuring and keeping data about anchor movement in order to allow later trajectory evaluation.
Oil production in deep water demands better technology for anchoring floating platforms so that new engineering solutions have to he tried. For this purpose, very new anchor technology that employs a special anchor type called Vertical Load Anchor (VLA) (O'Neill, Randolph and Neuhecker, 1997) arises. Differing from conventional anchors, the VLA has the ability to be very deeply embedded into the seabed so that the interaction with the mud provides the necessary force to hold the mooring line, almost straight upwards, contrary, to common anchors whose line must he tangent to the sea bottom and which cannot stand vertical loads. By using VLA, the mooring line from the anchor at seabed to the fair lead on the floating platform can have taut configuration, which decreases line length. As a good consequence, the ratio H/R, between water depth and anchoring radius, can be kept around unit, whereas conventional mooring needs H/R ~ 3, Considering economical and operational aspects, this solution has great advantages once it spends less rope and keeps the operational scenario cleaner. On the other hand the use of synthetic ropes is highly recommendable as, because of material elasticity, they ensure the necessary mooring dynamic compliance, even for taut lines.
