Golfinho Project-Well Construction

Abstract The Golfinho Field is located in the Southeastern coast of Brazil, at water depths between 1,300 and 1,640m and is the first offshore deepwater development in the Espirito Santo Basin. The field has two main oil reservoirs - Campanian, with 40° API oil, and Maastrichtian, with 28° API. The field has been developed through horizontal wells. This paper describes some drilling and completion operations, the equipment used, as well as some lessons learned during the course of the work. Two kinds of completion systems - conventional and one-trip completion - have been used. Open Hole Gravel Packing was also installed in all the wells to control sand production. The wells which at first flow naturally are also equipped with continuous gas lift and electrical submersible pumps to be used later when artificial lift becomes necessary. Introduction The Golfinho Field was discovered in July 2003 by the wildcat well 1-ESS-123. Located at water depths between 1,300 and 1,640 m, it is 80 km away from Vitoria, the capital city of the state of Espirito Santo (see Figure 1). The field was declared commercially feasible in January 2004, after which the Brazilian Regulatory Agency granted PETROBRAS with a license for exploitation. This would be the first deepwater oilfield development project in the Espirito Santo Basin. Two Floating Production Storage and Offloading (FPSO) units were then leased by PETROBRAS to develop the Golfinho Field. The first one, FPSO Capixaba, was leased from the Swiss SBM to develop Module 1 of the Golfinho Field; and the second, FPSO Cidade de Vitoria, was leased from the Italian Saipem to develop Module 2. Both have a maximum throughput of 100,000 barrels of liquid per day. Module 1 comprises five production wells and three injection wells, all of which have already been drilled and completed. Three of these producers as well as the three injectors were drilled into the Campanian reservoir, with the two other producers being drilled into the Maastrichtian reservoir. Module 2 comprises four producers in the Maastrichtian reservoir, all of which have already been drilled and completed, and four injectors also in the Maastrichtian reservoir, which should be drilled and completed by June 2007. The project also includes the completion of well 1-ESS- 132, in October 2007, to produce gas from the Santonian reservoir to FPSO Cidade de Vitoria (see Figure 2). Figure 1 - The Golfinho Field (available in full paper) After connecting well 7-GLF-1HA-ESS to FPSO Seillean, production started, in February 2006, to collect data to allow a better development plan for Module 2. This was the first deepwater light crude to be produced in the Espirito Santo Basin. In May 2006, Module 1 started producing with FPSO Capixaba, to which three producers and three injectors are presently connected in the Campanian reservoir. The two producers in the Maastrichtian reservoir are yet to be connected. Module 2 should start producing with FPSO Cidade de Vitoria by June 2007, then consolidating Espirito Santo as the second largest crude-producing state in Brazil.