Last December, OE carried a report by the National Iranian Gas Company on the key facets and status of its massive, 24-phase South Pars gas field development in the Persian Gulf. Here, with the help of local contractor IOEC, we put together a photo-review of recent offshore installation work on the phases currently progressing.
Established in 1993 as Iran’s first offshore general contractor, Iranian Offshore Engineering & Construction (IOEC) has been heavily involved in the South Pars gas field work for client Pars Oil & Gas. With the addition of its pipe coating facility in 1999, IOEC embarked on an offshore services expansion programme which continues to this day and the company now lays claim to being able to provide projects with full marine fleet support for pipelaying, platform installation, hook-up and commissioning.
‘The South Pars offshore view has been changed by a number of events during the last six months,’ Nima Shirzadi, IOEC’s head of planning and project control on South Pars 15 and 16, tells OE. The latest offshore work campaign on those phases, and now being replicated in phases 17 and 18, calls for the installation of six jackets and decks including two wellhead platforms, two relief platforms with associated bridges and supports plus 32in pipelines with 4in piggyback lines. The pipelines on 15 and 16 are both 230km long, and 213km long on 17 and 18. Topsides fabrication for all four phases is now under way. EPC contractor for the platforms is SAFF & ISOICO, with IOEC taking the offshore leadership role as pipelines EPCI contractor and handling platform installation in 70m of water.
Between June 2009 and January 2010, four four-leg main jackets ranging in height from 74m to 79m and weighing in total 13,750t, were installed. Three of them (for phases 17, 18 and 16) were installed by IOEC and the fourth (for phase 15) by SAFF as subcontractor of IOEC. The phase 17 jacket including piles and appurtenances weighed in at about 3600t, while for phases 18, 16 and 15 respectively the weight was around 3700t, 3200t and 3250t. All four jackets were installed by the AB-1200 vessel using the launch method and through-leg 60in piles. Total weight of piles for each jacket was around 1700t.
Meanwhile, under phase 12, the IOEC work programme requires fabrication – now under way – and installation of the 4780t topside sections for three platforms under EPCI contract, including associated bridges and supports, as well as the installation of 437km of 32in pipe in three lines (A: 148km; B: 139km; and C: 150km) and a 4.2km, 30in line for the single point mooring and PLEM.
Another IOEC vessel, the multipurpose C-Master, has been kept busy on South Pars pipeline installation work. With its advanced hull design and overall length of 203m including stinger, this DP3 vessel can serve in pipelay, platform installation and accommodation vessel mode and is equipped for diving, pile driving, flexible pipelay and/or subsea installation work. The C-Master pipelay spread includes a portside mounted S-lay system with capacity for 4-48in pipe and three 60t SAS tensioners. IOEC says the vessel’s best pipelay performance to date is a rate of 4.2km/day for 10in diameter pipe.
At South Pars over the six-month period, the vessel completed the shore pull for six lines: three 32in and one 30in pipelines for the phase 12 project and the two 32in lines for phases 15 and 16.
According to Nima Shirzadi, C-Master carried out the shore pull for four lines (with lengths ranging from 900m to 1200m) and 13km of conventional pipelaying under phase 12 in just 16 days – ‘another good record for the company’.
By mid-February, before demobilising to handle a shallow water pipelay assignment in the Black Sea, C-Master had completed the spm/PLEM line and 45km of the 32in line A for phase 12. The AB-1200, also equipped for pipelay, was mobilising to continue this work. OE