A New All Electric Subsea Control System Development

Abstract

Over the past few years a specific programme has focused on the development of subsea separators and a subsea water treatment and injection process composed of several modules and requiring a certain amount of new subsea technology (subsea barrier fluid-less water injection pumps, filters, special water analyzers, etc.). One of these technologies is the all-electric subsea control system. The all-electric versus the electro-hydraulic solution was selected for its inherent capability to:enable long step-out distances;run logics such as sequences and fast closed control loops involving subsea proportional valves;handle high frequency of simultaneous valve actuations;implement safety functions, including SIL certified, when required. Within the ongoing industrialization programme of the new technologies, a Joint Development Agreement has been put in place between two partners for the qualification of the open framework platform for the control of subsea processes. The development is pursued according to the API 17N and DNV RP-A203 requirements. The subsea control system is developed according to the approach to interface standardization, which is aimed at guaranteeing:–the interchangeability of modules coming from different vendors;–the reduction of physical interfaces;–the optimization of IMR intervention time. The technology mainly consists of:a qualified basic component platform to be used for project-based assembly;a complete set of tools such as web-server, condition monitoring server, integrated software development environment, etc.;a standard and user-friendly approach for software application development, based on P&ID graphic, in order to facilitate the sharing of software information between contractor and clients;standard industrial communication protocols (no proprietary protocols) accessible to all users, which are designed for easy interfacing of the control system with third party equipment. The JDA activity has concluded the Q1 qualification tests of electronic components and Q2 tests of electronic assemblies, pursuant to API 17F, as well as all the other qualification activities (tests and analyses) relevant to the non-electronic components (e.g. 40kVA subsea electrical transformer), according to the relevant technology qualification plan. Additional software packages have also been developed and successfully tested using the Test Driven Development (TDD) method. The qualification will be completed by Q1 2019 with integration tests of:–Topside Control System;–Subsea Power and Communication Distribution Manager;–Subsea Control Unit. The integration tests will allow to reach TRL 4 of the above subsea equipment, in accordance with API 17N.