Svetsaren 1/2008 - Esab

ground level, “roll up”, cable support and final
consolidation by the fixation of tubular elements.
The assembly sequence was established after structural
analysis of the faces and levels of the jacket.
Welding, mostly of circumferential joints, was performed
following strict quality criteria and productivity.
Wherever possible, the welding of the tubular
elements was executed in the pipe shop using the
submerged arc welding process (SAW). The
remaining welds were performed in the field using
TIG welding (GTAW) or stick electrodes (SMAW) for
root passes, and flux cored wires (FCAW) or stick
electrodes (SMAW) for filling and capping.
The jacket’s production complied with the
Petrobras norm N-1852 construction criteria
(Oceanic structures - production and assembly of
fixed units). This norm states that steels used in
construction should be classified in conformity
with Petrobrás norm N-1678 (Oceanic Structures
- steel). The jacket’s design temperature was
10°C. The API 2W-50 steel used in the production
of the jacket was re-classified in accordance
with norm N-1678.
Welding consumables
Welding consumables used in the construction of
the platform jacket were supplied in agreement
with the conditions defined by Petrobrás norm
N-1859 - Welding consumables with quality
assurance. In order to meet these requirements,
Figure 2. Overview of the jacket in its final assembly phase.
Table 1. PRA-1 technical data
Depth
Pumping capacity
Deck
106 metres
750 thousand bpd
67 metres x 53 metres x
41 metres
Number of modules 5
Accommodation
Investment
90 people
US $2.7 billion
Jacket
Steel API 2W-50
Figure 3. Joint geometry
Total weight
Height
Base
Top
7,500 tons (approx)
116 metres
56 metres x 56 metres
36 metres x 49 metres
44 - Svetsaren no. 1 - 2008