Marlim Field: Risers, Flowlines and Umbilicals Developed
Authors: Porciuncula Sergio Lima , Ribeiro Julio Eduardo Dutra , Goncalves Ricardo Celio Freire 
Published: October 2008

The production approach adopted for Campos Basin oil fieldshas been strongly based on subsea completed satellite wells, floating production units and oil offloading through oceanic terminals. Flexible flowlines, risers and umbilicals have played an important role in this scenario, gradually building an outstanding reputation of reliability and cost-effectiveness. With a background of more than 3,500km of flexible lines and umbilicals already deployed in water depths ranging from 100m up to 1853m (present world record), it is natural that the "flexible solution" has been adopted for almost the totality of Marlim giant field applications.

This paper encompasses the technical evolution of flexible flowlines, risers and umbilicals, highlighting some milestones as world records and pioneer applications, installation and pull-in procedures, keeping the main focus over projects in Marlim field. The adoption of new products like protection against coral, IPU (Integrated Pipe and Umbilical), collapse resistant hoses for chemical injection, etc., is also presented. The paper reports the installation of a 10-inch gas export steel catenary riser (SCR) on platform PETROBRAS-18, as the first of its kind on a semi-submersible unit in the world. New trends under evaluation like the use of tension leg riser system and long length deepwater bundles installed through controlled depth tow method (CDTM), both considered as competitive solutions compared to flexible lines, have their scenarios presented and discussed in the paper.

The paper also emphasizes the partnership between PETROBRAS and suppliers, contractors, universities and operators around the world, that made it possible to overcome challenges faced to bring Marlim field production onstream. Problems that occurred on the course of operations are also discussed.

Introduction

After the first hydrocarbon discovery in Campos Basin on Garoupa field in Nov/1974, followed by Namorado and Enchova, more than 30 Floating Production Systems (FPS) were designed and installed in water depths (WD) ranging from 100m up to 1853m at present.

Many of those FPS have ceased operation and have been shifted to other locations, evidencing the great flexibility of this kind of production system and also remarking one of the main unsurpassed virtues of flexible lines: their ability of being recovered, re-wound and re-installed in new projects or new tracks.

Marlim field was discovered in Jan/1985. Due to the reservoir magnitude it was decided to adopt a phased development approach. Phased developments result in the anticipation of revenues that contributes on financing the subsequent phases. The production has come onto stream on March/1991, by means of a so-called Pre-Pilot Production System installed on board of the semi-submersible platform Petrobras-13. The floating unit was anchored in 640m WD and connected to two satellite wells on 721m and 752m WD, through flexible lines, and the oil was exported by means of a 8-inch flexible riser to a shuttle vessel on a CALM buoy. This system was very helpful on gathering advanced information about Marlim reservoir behavior, allowing good optimization on coming phases. It was replaced on July/1992, after 18 months from its startup, when the Pilot Production System was installed based on semi platform Petrobras-20.

The complete development of Marlim field will be achieved by the installation of eight units, as shown in Fig.1. It is worthwhile to mention the existence of adjacent oil fields that will have their development related to Marlim: Voador, South Marlim and East Marlim fields.