Jerry Lee profiles the development of Brazil’s giant Lula field, offshore Rio de Janeiro.
The FPSO Cidade de São Vicente was brought in to perform extended well tests on a Lula NE well in 2011.
Lula, Brazil’s first supergiant oil field, was described as “the second independence of Brazil” by the former Brazilian president Luiz Inácio Lula da Silva. Estimated to contain a total recoverable volume of 8.3 billion boe, the pre-salt carbonate reservoir is 250km off the southeast coast of Rio de Janeiro, beneath 2126m (6975ft) of water and 2791m (9156ft) of soil, rock and salt. Developing the field required many challenges to be overcome, some of which were included in a presentation covering the Lula Nordeste (NE) pilot project at the 2016 Offshore Technology Conference (OTC) in Houston.*
Originally known as Tupi, Petrobras made the ultra deepwater discovery in 2006 from the 1-RJS-628 wildcat well drilled in block BS-M-11 in the Santos Basin, where they found 28°API oil that was both light (high gas to oil ratio) and sweet (low sulfur content). In 2010, Tupi was renamed Lula, after the former Brazilian president, and declared commercial in December that year.
Comprised of the Tupi and Iracema (a sub-structure of Tupi discovered in 2009) areas, Lula is part of the Santos Basin Pre-Salt Cluster (SBPSC), which currently produces 1 MMb/d, according to Petrobras.
The BS-M-11 consortium is developing Lula. Petrobras is the operator and has 65% interest; BG E&P Brasil, a Shell subsidiary, has 25% interest; Petrogal Brasil has the remaining 10% interest.
Eager to tap into the Santos Basin’s vast reserves, the consortium decided to fast-track Lula’s development. However, when Lula was discovered, it was only the second discovery on the SBPSC. This meant that the consortium had to not only cope with the challenges of developing an ultra deepwater field, but there would be no infrastructure in place and little information to aid them. The project’s capital expenditure would be immense, so uncertainty and risks would need to be at a minimum.
According to the OTC presentation, Lula would be developed in phases, a strategy familiar to Petrobras, which would allow the learnings to be applied on future projects, progressively reducing risk. In the first phase, static and dynamic reservoir data would be collected through appraisal and reservoir data acquisition wells, drill stem tests (DSTs), extended well tests (EWTs) and pilots systems. Using this data, phase two would initially see definitive production systems put in place and later followed by new technologies to enhance production.
At Lula NE, one of the two Lula pilot projects, acquiring data and gaining production experience in the pre-salt area through different methods of secondary recovery were among the primary objectives. Secondary objectives included testing new equipment and technologies as well as an alternative subsea gathering system using uncoupled buoy supported risers.
SBM Offshore’s twin FPSOs pass in Guanabara Bay as Cidade de Maricá departs from and Cidade de Saquarema arrives at Brasa shipyard, Niteroi, Rio. Photo from SBM Offshore.
Lula NE Pilot
The Lula NE pilot is in the northeast area of the field and was the second pilot installed on Lula. Exploratory drilling of the first well, 3-RJS-662A, was completed in 2009. A DST showed a high productivity index and no flow barriers. The well was followed up by a reservoir data acquisition well, 8-LL-1D-RJS, 4.2km away, which showed high injectivity and transmissibility between the two wells.
More information was still needed, and as part of the development plan, BW Offshore’s floating production, storage and offloading (FPSO) unit Cidade de São Vicente was brought to 3-RJS-662A to perform an EWT. The EWT was conducted from April-November 2011 and produced approximately 2.8 MMbbl.
Later in the development project, 3-RJS-662A would be used as a gas injection well, and 3-RJS-662A would be used as a water-alternating-gas (WAG) injection well.
A large number of fluid samples were also taken from the field and studied to improve field modeling and simulations. And to reduce simulation time, for fast-tracking the field development, a large computer cluster was acquired. Although this was a costly investment, it provided great value to the project, helping to modify the development plans so that low and high GOR/CO2 wells were better assembled preventing gas processing restrictions and more complex FPSOs.
The FPSO Cidade de Paraty sails away from Brasfels Shipyard.Photo from SBM Offshore.
On Lula NE, investment in information gathering was higher than average and was necessary in order to develop a robust development project. In addition to the fluid samples, these included, but aren’t limited to, complete logging sets, cores, lateral rock samples, and daily pressure and temperature measurements. From this data, the consortium approved of the Lula NE plan, which consists of eight producers, five WAG injectors and a gas/ CO2 injection well. Some producers would have intelligent completions, to help maximize plateau production, and two subsea WAG manifolds would be used to connect four of the five WAG injectors to the FPSO.
Early on in the project, the lack of proven subsea technology that could handle the project’s demands was recognized. As a result, a buoy supported riser concept was developed as an alternative pre-salt subsea system. The concept would require two buoys, eight buoy foundations, 16 tethers, 15 steel catenary risers (one acting as a spare), for the production and injection lines, that would end at pipeline ends terminations, and riser anchoring piles. With this system in place, the wells would be connected to the buoys through the steel catenary risers, and the FPSO would be connected to the buoys using flexible jumpers.
The Lula NE FPSO, meeting the needs of a host of technical challenges, has been designed with the capacity to process 120,000 bo/d, 120,000 b/d of produced water, and 5 MMscm/d of gas. CO2 would be removed for reinjection, and gas would be separated for fuel gas, reinjection, lift gas, or export via a gas pipeline.
The FPSO Cidade de Paraty, has been on production at Lula NE since June 2013 and has reached its plateau production in September 2014. The wells have shown good productivity and injectivity; the highest production from a single producer exceeded 35,000 b/d, while the highest injection rate exceeded 50,000 b/d at a single injector.
The Lula projects following Lula NE have since benefited from the static and dynamic information gathered there.
Elsewhere on Lula
Prior to the Lula NE pilot project, the Lula project came online in October 2010 via the FPSO Cidade de Angra dos Reis, which has the capacity to process 100,000 bo/d, 150 MMscf/d of gas, and inject 100,000 b/d of water. The Lula pilot area is being produced through five production wells, and five injections wells: one gas injector, two water injectors, and two WAG injectors.
In October 2014, production began from the Lula/Iracema Sul Area via the FPSO Cidade de Mangaratiba, which can process 150,000 bo/d and 280 MMscf/d of gas. The FPSO is connected to eight production wells and eight water injection wells.
Almost one year later, in July 2015, production from the Lula/Iracema Norte Area began five months ahead of schedule through the FPSO Cidade de Itaguaí, which can also process 150,000 bo/d, 280 MMscf/d of gas, and inject 264,000 b/d of water. The Lula/Iracema Norte Area produces to the FPSO through eight production wells, with the help of nine injection wells, and will export natural gas through a subsea gas pipeline.
Progress with the field development continued in 2016 with two more FPSOs coming online: Cidade de Maricá in February on Lula Alto, and Cidade de Saquarema in July on Lula Central. Both FPSOs are capable of processing 150,000 bo/d and 6 MMcm/d of gas. Plans for the development of Lula Alto includes 10 producing wells and seven injection wells, while Lula Central development plans include 18 wells split between producer and injector wells.
This year, Petrobras has plans to start production on Lula Sul and Lula Norte via the FPSOs P-66 and P-67, respectively. Then in 2018, Lula Ext. Sol will be brought online with FPSO P-68.
*This article is adapted from De Moraes Cruz, R. O., Rosa, M. B., Branco, C. C. M., de Sant’Anna Pizarro, J. O., & de Souza Silva, C. T. (2016, May 2). Lula NE Pilot Project - An Ultra-Deep Success in the Brazilian Pre-Salt. Offshore Technology Conference. doi:10.4043/27297-MS