First oil from new Petrobras well in ultra-deep Lula field; new buoyancy supported riser system deployed
Petrobras reports beginning production from well 7-LL-22D-RJS in the Santos Basin’s Presalt Lula field (Lula NE Pilot area). This ultra-deep well—the wellhead is located at a water depth of 2,130 meters (6,988 feet)—with a production potential of 26 thousand barrels per day (bpd), is connected to FPSO Cidade de Paraty via a new platform-connection system deployed for the first time in the Lula field. Using this system, the riser section of the production pipelines is supported by a submerged buoy at a water depth of 240 meters (787 feet).
|A rendering of one of the RSB buoys. The pipes to the left rise to the FPSO; those on the right drop to the wells. Tethers are in the middle. Source: Subsea 7. Click to enlarge.|
During 2014, a further 6 wells will be connected to the platform (4 production wells and 2 injectors) using the new Riser Support Buoy (RSB) (or Buoyancy Supported Riser, BSR) system, ramping up FPSO Cidade de Paraty to full production capacity of 120,000 barrels of oil per day (bpd) in the third quarter of 2014.
Petrobras awarded Subsea 7 a US$1 billion SURF (Subsea, Umbilical, Riser and Flowline) contract for the engineering, procurement, installation and pre-commissioning of four submerged buoys each weighing about 2,000 tonnes to be installed at approximately 250 meters below the sea level, buoy foundations and associated tethers; 27 steel catenary risers of 3.9 km; 21 x associated pipeline end terminations (PLETs) of which 18 7.5-inch production lines, three 9.5-inch water injection lines and six 8-inch gas injection lines; 27 x anchor suction piles; and 4 x monitoring systems for buoys and SCRs.
When deployed, the RSB is immune to the FPSO platform movements. This innovation means that rigid steel pipes (Steel Catenary Risers – SCR) can be used in some parts of this ultra-deep water project.
The rectangular buoy measures 40 x 52 meters and weighs 1,936 metric tons. It is attached to the seabed by means of eight 1,828-meter (5,997-foot) steel tendons, each fixed to one of four stakes in the seabed.
Subsea 7 built and deployed the system. The buoy is capable of stabilizing pipes from up to 4 production wells and 3 injection wells. Deployment of the system commenced on 19 December 2013 and was completed on 7 February 2014. Deployment of the SCRs was completed on 1 April 2014, for connecting the first three production wells.
Connection of well 7-LL-22D-RJS to the FPSO was completed on 5 May 2014, when the flexible pipelines were deployed. A second buoy is already in position and ready to stabilize the SCRs used for production and injection.
FPSO Cidade de Paraty went into operation on 6 June 2013. Well 7-LL-11-RJS was connected directly to the platform and produces some 30,000 bpd. The Lula field is operated by Petrobras (65%) in partnership with BG E&P Brasil Ltda (25%) and Petrogal Brasil S.A (10%).
|FPSO Cidade de Paraty. Source: Petrobras. Click to enlarge.|