Roncador Field: The Operational Experience on 1-RJS-436 A: The Pilot Well
Authors: e Silva Jayme Eduardo Miranda 
Published: October 2008

This paper will present the operational performance of the long-term production test project: the FPSO Seillean and the Early Production Riser System, today in operation at the Pilot Well of Roncador Field, the 1-RJS-436 A.

First, a brief description of the Reservoir characteristics and the well completion design. The 1-RJS-436 A is the Petrobrá is best vertical producer well (including our highest flowrate per foot of a gravel pack equipped well).

After that, the subsea equipment Installation, a description of the Christmas Tree and the Early Production Riser System focused basically on the installation process, presenting the problems and solutions adopted (like Christmas Tree sealing and Emergency Disconnect System failure).

To finalize, production operation, a description of the system performance since the beginning of production in January of 1999 until the present days. The major highlight will be given on the strong points, like the DP excellent performance, allied to the total success in the offloading operations, which brought a high global efficiency to the System.

It will be described here also the failures caused by the project technological innovations, like the low isolation in the electric lines of the Subsea Control Module. After that, I will present the failures occurred due to the technology already known, typically used in short time operations and used in this system, without special adaptations for the long-term test, like the Tensioning Riser System failure and the problems of the Emergency Disconnect Package connector.

Introduction

The Dynamic Positioning FPSV (Floating Production and Storage Vessel) Seillean (Fig. 1) was built in Belfast in 1990, aiming to produce small and isolated reservoirs from one or two submarine wells connected to the ship through a Wet Christmas Tree system and a rigid column to its moon pool.

In December 1997, Technical and Economical Viability Studies recommended hiring Seillean in order to collect precious information of the reservoir aiming to guide the exploitation of Roncador Field using Seillean as a Pilot Plant.

Seillean was then hired for a six-year operation period. After going under a series of adaptations in 1998 (to operate in up to 2,000 m water depth, as well as an FPSO according to PetrobrÃ¡s requirements), Seillean began operating in the well 1 RJS 436 A at 1853 meters of water in Roncador Field.

Seillean shall remain on the present location until September 2000, when it will sail to new location at Module II of Roncador Field Development Project, and the present well will be put on stream to the Floating Production Unity P-36 (ex-Spirit of Columbus) as part of the Definitive Development Project of Module I of the same field.

Besides structural modifications on the ship to support the increase of the operation water depth (from 200 to 2,000 m), it was necessary to alter all Subsea control system, from hydraulic to multiplexed, and it became evident that the submarine system was the critical part of the Project, in terms of complexity as well as in terms of deadlines.