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

Seabed preparations, PGN

The pipeline between Pulau Pemping, Indonesia, and Pulau Sakra, Singapore, is the final link of the transportation system for natural gas from onshore fields on South Sumatra to Singapore. The successful completion of the Engineering, Procurement and Construction contracts for the 27-kilometers 28-inch gas pipeline with a 96-core fibre optic cable in one of the busiest ports and shipping traffic zones of the world marked a milestone for Boskalis. The scope of work comprised not only seabed preparations and protective rock berm installation - Boskalis Offshore core activities - but also pipeline manufacturing and installation.


Deepening of the Eems-pipeline

The 42" Eems pipeline is part of the pipeline connection between the gas cleaning and drying plant of Phillips Petroleum at Rysumer Nacken in Germany, and the natural gas pipeline network in the Netherlands. The gas is obtained from the Ekofisk gas field in the Norwegian region of the North Sea. The pipeline crosses the morphologically dynamic Eems estuary over a length of 4 km, passing both the deep shipping lane ‘Oostfriesche Gaatje’ and the shallow sand bank ‘Paap’.

Development gas export pipeline,
Hibiscus to Point Fortin

The NCMA Development Project comprised the development of the North Coast Marine Area, which is located in the Caribbean Sea and Bay of Paria, Trinidad. The project included the installation of a 24" Gas Export Pipeline from the Hibiscus Platform to a landfall at Point Fortin. From the landfall the pipeline was routed by directional drilling and by surface laid pipeline, to a termination point in the Atlantic LNG Terminal at Point Fortin. As part of this project Boskalis was awarded the contract for the provision of landfall, directional drilling and onshore pipeline installation and testing of the 24" gas pipeline system.


Hanze F2a Development Project

Hanze, 200 kilometers offshore Den Helder in block F/2 of the North Sea, is the first operated development in the Dutch sector by Germany's Veba Oil. The oilfield reserved approximate 34 million bbl, plus 40 bcf of associated gas. 

Installation gas pipeline, Takoradi

Late November 1998 Boskalis was awarded a subcontract for the installation of two marine pipelines to supply and discharge cooling seawater for the Takoradi thermal power plant that was under construction for the Volta River Authority, near the village of Aboadze approximately 20 kilometers north-east of Takoradi, Republic of Ghana.


Re-insulation Gannet 'C' Bundles, North Sea

The Gannet 'C' satellite field, which is located in the North Sea at 112 miles East of Aberdeen in 95-meter water depth, comprises four drill centres, each having one or more producing wells. The drill centres are connected to the local platform Gannet 'A' by four flowline bundles with a total length of 10 kilometers. A glycol-based gel, filling the annulus of the Gannet 'C' carrier pipe, insulated the individual flow lines. Prompted by degradation of the gel and the resulting drop in oil and gas arrival temperatures at the platform, an EPIC project took off for a re-insulation system. The objective of the re-insulation system was that it should provide sufficient insulation to the bundles in order to safeguard production during the total field life of Gannet 'C', being a minimum lifetime of 15 years. Boskalis Offshore was supported by Hydronamic - the in-house engineering department.