Identification And Quantification Of Geohazards For Deep Water Sites

Deep water developments by means of floating systems involve spread moorings, manifolds and in-field pipelines and cover large areas of the seabed. Also, deep water sites are often located on continental slopes, thereby still increasing the seabed area which may influence the installations. In this paper, a novel methodology is developed to quantitatively assess geohazards and define acceptance levels or the need for remedial measures. The method is based on state-of-the-art practice for industrial installations, is applicable to offshore installations and involves the following four phases: hazard identification, classification of criticality levels, frequency of occurrence and evaluation of risk level. The result of the analysis is an acceptance matrix which highlights the eventual need for remedial measures. Application of the method is illustrated with an example of a deep water site which is currently under development. The applicability of the method, eventually in a simplified form, to conventional platform sites and pipeline routes is also illustrated.