Offshore-Connectivity Solutions for the Oil and Gas Industry

Abstract

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 117254, "Offshore Connectivity and Ultra-Long Tiebacks Solutions for Oil & Gas," by A. Lecroart, R. Michel, and J.P. Odier, Alcatel-Lucent Submarine Networks, originally prepared for the 2008 SPE Asia Pacific Oil and Gas Conference and Exhibition, Perth, Australia, 20-22 October. The paper has not been peer reviewed. The oil and gas industry is forced to go into deeper water further offshore to find new oil or gas. At the same time, the industry is placing more emphasis on integrated operations driven from onshore control centers. Highly reliable communications solutions are required to fulfill these objectives. Large bandwidth and low latency links between offshore facilities and the shore are essential for communications to all company personnel and contractors engaged in the offshore development areas. The full-length paper describes overall solutions to address these needs and reviews available technologies. Introduction Exploration and production of offshore fields is evolving and makes use of various modes of communication. Many oil companies are establishing operations centers where technical expertise is located. Telecommunications from the field to these centers is becoming critical, and solutions exist to make communication both efficient and dependable, with a choice of different technologies listed in Table 1 in the full-length paper. Dry/Dry Solutions The dry/dry solutions adapt the traditional shore-to-shore telecommunication application so that it can be used with different types of offshore assets such as a fixed platform or floating assets such as a tension-leg platform, a spar, or a floating production, storage, and offloading vessel (FPSO). One would prefer ring or loop architectures connecting each asset with its own spur by use of a branching unit (BU). The system is designed to allow the platforms to be independent and limits the number of risers per asset to one, compared to a simple daisy chain. For the last-mile connection, a dynamic riser is required to access floating assets, while a simple J-tube may be sufficient with shallower fixed structures. Another complexity may come from the use of fiber-optics (FOs) rotating joints because the latest generation of FPSOs tends to adopt a turret architecture, allowing the vessel to rotate freely. In most cases, studies are required to validate and qualify the riser design according to the requirements of the structure and the local weather conditions. A second approach is to equip an umbilical with fiber and allow the last-mile connection to take place subsea with a combination of wet-mate connectors and subsea manifold. In this case, a special cable termination is provided allowing remotely-operated-vehicle (ROV) handling of the wet-mate connector by use of a length of flexible hose. Both approaches are valid and will solve the last-mile issue adequately.