An Integrity Management Strategy Based on Flexible Risers Conceived to Be Self-Monitored

Abstract

Many of the current practices applied for offshore production managing emphasize those aspects related to the efficiency of oil & gas production and exportation. Nowadays, due not only to the inherent technical challenges associated to deep-water applications but also to the increasing importance of the HSE aspects and requirements faced by the industry, a crescent demand to implement a philosophy which focalizes safety, reliability and integrity of their subsea flowing systems is taking place. The handling of monitored data in order to help the pipe operator to control fluid transportation throughout flexible pipes is an old practice performed by Petrobras and other oil companies in the world. However, the idea of acquiring a product which has been conceived, designed and manufactured with both intrinsic monitoring and expert systems is a recent idea. The tendency of the main flexible pipe manufactures is normally to face the problem from the traditional point of view: those systems are considered dissociated one from the other and as appendices to be installed, in the field, after system connection and start-up. Experience demonstrates that the installation of those systems during the operation phase has a number of limitations, restrictions, and associated problems. The main objective of this paper is to present an integrity management strategy based on the concept of the self-monitored flexible riser. Self-monitoring is understood as the own capacity of a product (flexible pipe and components with built-in devices) to acquire data about itself and make use of data from the internal and external environments, during its service life. Monitored data is then processed in order to generate relevant information for the fluid transportation business. The basic premise is to select, during product conception phase, some key-parameters to be further monitored, during the operation phase. The selection is determined by technical criteria depending on the potential failure mechanisms and modes related to the particularities of each different application.