Flexible Pipe for Ultra-Deepwater Applications: The Roncador Experience

Abstract

Abstract The exploration and production (E&P) segment of the petroleum industry has progressively been led to act deeper. In Brazil, where the deep water (400 to 1,000m WD) and ultra-deep water (1,000 to 2,000m WD) have been the segments responsible for the major portion of the overall country petroleum production (approx. 1.3 MMBPD), one can find in Campos Basin the main arena for the pioneer deployment of new technologies. CSO has been working in this environment as a strong partner of Petrobras, helping them to reach their main objectives, from engineering to product manufacturing and supply, installation and commissioning. This paper will describe: The technical solutions incorporated in the design of flexible lines of up to 9.2" in 1,500m WD and 6" in 2,000m WD, well in excess of any previous design. The installation procedures developed and the up to date installation experience in the field, the challenges encountered and lessons learned. It will also mention the strategies that are being adopted by Petrobras and CSO to overcome the main technological ultradeepwater challenges, to go beyond the 2,000m WD mark. Introduction Petrobras history in Campos Basin is discerned by a permanent challenge to overcome deeper water depths. The discovery of giant fields, like Marlim, Albacora and more recently, Roncador, in water depths ranging from 1,500m up to 2,000m, has demanded the development of new technologies, mainly the optimization of subsea hardware, installation and operational procedures. Flexible pipes have played an important role in the history of oil production in Brazil, gradually building an outstanding reputation of reliability and cost-effectiveness. No other oil province worldwide has applied flexible pipes so intensively as Campos Basin, where up to the present date there are about 2223km of risers and flowlines installed. For Petrobras, flexibles is the best way to make feasible production of oil fields in a short time, even before the reservoir delimitation and subsea layout consolidation, as they can be easily recovered, inspected, repaired, re-laid and connected in new sites. Flexible pipes are composed of unbonded layers of plastic and steel, each layer being designed to resist to a specific loading, such as: crushing loads, internal pressure, collapse pressure, axial loads, torsion and so on and may be designed both for dynamic (risers) and for static (flowlines) applications. The recent advances on the application of flexible pipes in deeper waters associated with a significant CSO R&D effort on the improvement of current structure design has shown that the adoption of flexible will continue to have a large demand in Campos Basin. The main goal of this paper is to describe how Petrobras has dealt with the necessity of starting oil and gas production on Roncador ultra-deep waters in a short period of time, and what has been done by CSO and Petrobras to overcome the main challenges of this field.