To main content

Mooring replacement phase 2, Zafiro Producer

Mobil Equatorial Guinea Incorporated, an affiliate of ExxonMobil, entered into a contract with Boskalis for the Zafiro Producer Mooring Replacement Project Phase 2. The Zafiro Producer is installed in 180 m (590 ft)water depth approximately 74 km (40 nauticalmiles) west of Malabo, Equatorial Guinea.

The Zafiro oil field is located in the 500,000-acre Block B, 68 km (42 miles) WNW of Bioko island, Equatorial Guinea, adjacent to the international border with Nigeria. Water depths range from less than 300 ft to greater than 5,000 ft. The Zafiro-1 discovery well was drilled in February 1995, testing at 10,400 barrels per day (b/d). Three subsequent wells showed the reservoir to be relatively shallow (around 5,000 ft), and low pressure, with a bottom-hole shut-in pressure of 2,800 psig. The Zafiro Producer is a converted 268,191 dwt VLCC (very large crude carrier). The tanker was built in 1973, with an overall length of 331.5 m, a breadth of 56 m and a depth of 26.4 m. It has a draught of 20.5 m fully loaded, or 8.3 m ballasted. Early reservoir evaluation indicated that a 40,000 b/d rate could be expected from the planned eight wells, requiring the installation of an 80,000 b/d process plant, a 40 MMSCFD gas flare capacity and storage for 1.7 MMBBL of oil.The FPSO was installed in 1996 and later the storage capacity was taken over by the Serpentina changing the Zafiro Producer into a FPU (Floating Production Unit).

Mooring replacement

This 2015 campaign concluded a partial mooring replacement for ML 1, 2, 4, 8, 9, 10, 11 and 12 as well as a complete mooring replacement for ML 3. The project scope of the Phase 2 mooring replacement consisted of the following:

  • Installation of two new anchors utilizing a reaction anchor for tensioning;
  • Inspection of specified mooring components;
  • Change out of most, if not all, components for a full replacement of two of the mooring lines;
  • Change out of specified components for a partial replacement of seven of the mooring lines;
  • Removal of samples for forensic analysis.

Related projects

Selected filters

Ineos IRM 2018

Boskalis Subsea Services was contracted by INEOS E&P A/S for the 2018 Inspection, Repair and Maintenance (IRM) campaign, involving the preparation and execution of 20-off scopes on various assets.


Haven Jack-up upgrade

The Master Marine accommodation unit HAVEN required an upgrade for operations at the Johan Sverdrup Field.


DNO Oman block 8 LTD

DNO Oman Block 8 Ltd (DNO) is the operator of the Bukha Field, offshore Khasab, Oman. DNO entered Oman in 2012 and operates the country's only producing offshore fields on behalf of Omani Oil & Gas ministry. Boskalis Subsea Services (BSS) in recent years have assisted DNO with lifting a flare boom onto the WB Platform, making use of a DP2 offshore vessel, also Boskalis provided diving and inspection services to DNO for their SPM Offshore RAK, UAE.


Transport and installation Aasta Hansteen
spar platform

For the Statoil Aasta Hansteen project, Dockwise has transported the newbuild spar hull from the HHI fabrication yard in Ulsan, South Korea to the offshore discharge location near Høylandsbygd, Norway. The spar is the world’s largest spar ever built to date. 


Transport and installation turbine foundations offshore wind farm, Wikinger

The Wikinger offshore wind farm has been developed by Iberdrola in the Baltic Sea area, within the German Exclusive Economic Zone (EEZ). The offshore site is about 34 km northeast of the island of Rügen, and covers an area of roughly 50 km², within which 70 wind turbine generators (WTG) of 5 MW and one offshore substation (OSS) are being installed. The water depths for installation range between 36 and 42 meters. When completed the windfarm will deliver 350 MW electrical power to the German national grid. The transport and installation of the 70 WTG foundations and the piles for the OSS has been carried out by Boskalis.


Offshore wind farm
monopile installation,
Veja Mate

Boskalis is close to completing one of its latest and most significant offshore wind projects - Veja Mate, in the German North Sea. The project involves handling and installing the biggest monopiles in the industry – weighing between 1,230-1,302-tonne a piece – using the biggest pile gripper frame and pile driving hammers in the industry with a brand new vessel, which also happens to be the biggest in the sector. Once complete, the offshore wind farm will produce over 1,6 TWh of green, renewable electricity annually.