TOP 5 PROJECTS
Petrobras brings deepwater
Sapinhoá oil field online
Gene Kliewer
Technology Editor,
Subsea & Seismic
When Petrobras brought the deepwater Sapinhoá oil feld on production early in 2013, it put added attention on what already is one of the hottest plays in the world. Further- more, it brought with it the implementation of the new concept of a buoyancy supported riser system.
Petróleo Brasileiro S.A. initiated commercial production from the Sapinhoá feld in block BM-S- 9 in the presalt Santos basin through the Cidade
de São Paulo FPSO.
Well 1-SPS- 55, the frst one connected, began to fow at 15,000 b/d of
oil. It was restricted to that fow rate until the natural gas processing and
reinjection systems were commissioned, at which point the well could
fow at 25,000 b/d. The oil is 30º API and Petrobras says it is of high
quality.
The gas not used for reinjection will be transported through the Sap-inhoá-Lula-Mexilhão gas pipeline to the Monteiro Lobato Gas Treatment
Unit in Caraguatatuba, on the coast of São Paulo state.
Ten more wells (fve production and fve injection) were scheduled
to go online, with peak production of 120,000 b/d expected in the frst
half of 2014.
Total recoverable volume from Sapinhoá feld is estimated at 2. 1
Bboe.
The FPSO is anchored in 2,140 m ( 7,020 ft) of water, 310 km (193 mi)
off the coast, and is capable of processing 120,000 b/d and 5 MMcm/d
(177 MMcf/d).
Looking ahead, Sapinhoá’s development plan calls for a second,
FPSO, Cidade de Ilhabela, to go onstream in the second half of 2014 with
the capacity to handle 150,000 b/d and 6 MMcm/d (212 MMcf/d).
Block BM-S- 9 is operated by Petrobras (45%), in partnership with
BG E&P Brasil Ltda (30%), and Repsol Sinopec Brasil S.A. (25%).
Riser buoy support
Petrobras conceived the buoyancy supported riser (BSR) system which
deploys submerged buoys at a midwater level below the FPSO. Subsea
7 was appointed to take the concept forward as part of a $1-billion SURF
contract.
Each BSR is a relatively fat, rectangular buoy weighing about 2,000
metric tons ( 2,205 tons), and installed 250 m (820 ft) subsea with eight
tethers anchoring it to the seabed. The buoys will support a total of 27,
3.9-km ( 2.4-mi) long steel catenary risers (SCRs) suspended in parallel
vertically to the seafoor, and connected to the FPSO via non-bonded,
fexible jumpers.
The BSR system is designed to absorb the dynamics from the FPSO,
resulting in minimized dynamic stresses on the SCRs, and making them
behave instead like a long, free-spanning pipe, with the main fatigue response arising from any vortex-induced vibration.
The SCRs’ dynamic response is low, which made possible use of
BuBi mechanically lined pipe. This is the frst such application installed
by reel-lay. It was made possible through a joint development program
by Subsea 7 and stainless steel manufacturer BUTTING.
Also integral to the BSR system is Subsea 7’s Angular Connection
Module (ACM) that connects the fexible jumpers to the pre-installed
buoys.
Because of the large quantity of risers, the buoys can take up different positions which results in a range of angles. The ACM allows
connections to be made at misaligned angles of up to 15°, said Subsea 7.
Field development
In January 2010, the Sapinhoá consortium agreed with the Scha-hin/Modec consortium to lease and operate an FPSO on the Sapinhoá oil feld for 20 years. The VLCC Radiant Jewel was converted into
FPSO Cidade de Sao Paulo. While COSCO converted the hull at its
China shipyard, BrasFELS did all the module installation, assembly,
and integration starting in 2012.
Petrobras carried out further tests to determine the size of the feld. In
December 2010, it began a fve-month extended well test at the feld using
the discovery well. In March 2011, however, Petrobras halted the EWT
due to a rupture in the riser connecting the well to the production platform.
Other suppliers
The contract to supply fexible gas injection lines, including top risers, intermediate and bottom risers, and fowlines, was awarded to
Technip. In April 2010, Aker Solutions was awarded the contract to supply 14 trees for the Sapinhoá feld. The scope of work included fabrication and engineering of the trees.
Keppel FELS won the contract to fabricate the topsides of the FPSO
in February 2011. In April 2011, Subsea 7 was awarded the contract
for supplying the riser systems.
Petrobras awarded an engineering, procurement, construction, and
installation contract to Saipem in May 2011 for gas export pipelines and
related infrastructure.
Parker Hannifn was subcontracted by Subsea 7 in June 2011 to supply sheathed tethering lines measuring 6,000 ft ( 1,829 m) to moor the submerged buoys.
In October 2011, Dresser-Rand was awarded a $700-million contract by
TUPI, a Petrobras operating company, to supply compression equipment
for eight FPSOs including the two in Sapinhoá.
Further development
This may not be the last of the work done in the area. Petrobras drilled a
discovery well nearby in the transfer of rights area called Southern Guará. The
third well, 1-BRSA-1045-SPS (1-SPS-96), found 27º API in a 93-m (305-ft) carbonate reservoir at 2,202 m ( 7,223 ft) with a TD of 5,760 m ( 18,893 ft).
Sapinhoá is in the presalt Santos basin. This presalt runs for 800 km
(≈500 mi) along Brazil’s coast and produces from beneath a layer of salt,
under about 3,000 m ( 9,840 ft) of water another 3,000 m to 5,000 m ( 16, 40
ft) under the seabed. •
The FPSO Cidade de São Paulo.
(Photo courtesy Petrobras)
