Determinação de massa adicional de estruturas submarinas com base em dados de campo

Abstract

The determination of the dynamic loads acting on subsea structures during installation represents a challenge for the offshore industry. When installed, underwater equipment and structures are exposed to cyclic loads arising from the installation vessel and fluid motions. In general, the methodology adopted by the industry to determine these loads generates conservative results, reflecting in oversized installation devices and in very restricted operational windows. In order to adapt the industry practice to the current offshore scenario, it is necessary to review the way which installation analysis of subsea equipment is being carried out, more specifically, the methods for determination of the hydrodynamic properties of these equipments. The objective of this work is to challenge the methodology currently adopted by the offshore industry for the determination of the added mass values used in installation analysis of subsea equipment. In order to achieve this objective, a methodology to determine the added mass of an subsea structure based on data recorded in the field is proposed. Values obtained through the proposed method are then compared against values calculated using the methods currently adopted by the industry, allowing to assess the impact of applying the current industry practice for added mass determination through a cost point of view.