The Polvo shallow-water field located in Campos Basin, Brazil, has been in operation since 2007. PetroRio, an independent oil and gas company based in Brazil, holds 100% interest in the field and serves as the operator.

The field was originally discovered by Devon Energy (60%, operator) and SK Energy (40%) in 2004 and produced first oil in July 2007. Devon Energy sold its 60% interest in the field to BP Energy do Brasil (BP) in May 2011, following which the latter assumed the operatorship of the field. Maersk Oil acquired SK Energy’s assets in December 2010 gaining 40% interest in the Polvo field.

BP agreed to sell its 60% interest in the field to PetroRio (formerly HRT Participações em Petróleo) in May 2013 and completed the transaction in January 2014. PetroRio became 100% owner of the Polvo field after acquiring the remaining 40% interest in the field from Maersk Oil in December 2015.

Location

The Polvo field is located in the BM-C-8 Block in the southern part of the Campos Basin, 100km east of the Cabo Frio, Rio de Janeiro state, Brazil. The licence area in which the field is located is spread over approximately 134km2 and has a water depth of approximately 100m.

The average production of the Polvo field was 9,191 barrels of oil equivalent a day (boed) in 2020.

Discovery and appraisal details

Devon Energy discovered oil in the Macaé Quissamã Carbonates of the BM-C-8 Block with the drilling of the 1-DEV-003-RJS appraisal well in 2001. Two appraisal wells, 1-DEV-004-RJS and 3-DEV-005DP-RJS, were drilled in 2004.

The third appraisal well 3-DEV-007-RJS drilled in 2005 confirmed the commercial size of the Polvo field, following which Devon submitted the field development plan to the Brazilian National Agency of Petroleum, Natural Gas and Biofuels (ANP).

Polvo field development details

The Polvo field development plan includes the Polvo-A fixed production and drilling platform comprising 16 wells, which produce using electric submersible pumps (ESP).

The Polvo-A platform is installed in 330ft (100m) of water and is connected to the Polvo floating production, storage, and offloading vessel (FPSO) by a flowline and an electrical umbilical.

Polvo field’s revitalisation plan

PetroRio initiated the three-phase revitalisation plan for the Polvo field in 2016 to extend the life of field and boost production. The field’s oil production was increased by applying enhanced oil recovery techniques under the first phase of the plan.

The second phase of the plan included the drilling of three wells to increase the volume of recoverable oil. The first well, POL-H, commenced production in May 2018, while the remaining two wells, POL-Z and POL-M, commenced production in July 2018 and November 2018, respectively.

Phase three of the plan was commenced in 2019 and included the drilling of the POL-L and POL-K wells, which started production in March 2020 and May 2021, respectively. The POL-L well targeted sandstone reservoir of the Eocene period in the Emboré Formation, while the POL-K well was also drilled in the Eocene reservoir.

Polvo and Tubarão Martelo fields tieback

PetroRio initiated tieback between the Tubarão Martelo and Polvo fields in 2020 to reduce the operational costs and environmental impact, while simplifying the production system and extending the economic life of both the fields. The tieback was completed in July 2021, creating a cluster of mature fields.

The cluster is expected to produce until 2037, as per a reserve certification report which considered 1P reserves.

PetroRio holds 80% interest in the Tubarão Martelo field and serves as the operator, while Dommo Energia holds the remaining 20% interest.

PetroRio holds the right to 95% of the oil produced by the cluster, which includes both the fields. The company will hold the rights to 96% of the oil produced by the cluster after the production of the first 30 million barrels. Dommo Energia is eligible to receive the remaining oil produced by the cluster.

Polvo oil field infrastructure

The oil produced by the Polvo field is processed by the Bravo FPSO, which was connected to the Polvo-A platform, following the tieback with the Tubarão Martelo field. The Bravo FPSO (formerly OSX-3 FPSO) was acquired by PetroRio from OSX3 Leasing for £106m ($140m) in February 2020.

The Bravo FPSO has been in operation at the Tubarão Martelo field since 2013. It has a processing capacity of 90,000 barrels of oil a day (bpd) and an oil storage capacity of approximately 1.26 million barrels.

The Polvo FPSO that was part of the original field development plan was disconnected from the field following the tieback.

Contractors involved

OSX3 Leasing awarded MODEC the engineering, procurement, installation, and commissioning contract for converting the OSX-3 FPSO into the Bravo FPSO. The scope of the contract included the topsides, hull and marine systems, and the turret mooring system.

Ramboll UK was contracted by Devon Energy to provide engineering and design services for the Polvo-A platform.

PetroRio chartered the Polvo FPSO from BW Offshore.