Goliat Oil and Gas Field, Barents Sea, Norway
The Goliat field is located in the production licence 229, in the Barents Sea, north of Russia and Norway. It was originally awarded in the Barents Sea in 1997, which was initiated in order to increase interest in the area as an oil and gas region.
The discovery well was drilled in 2000 and a total of five wells have so far been drilled. The licensees of PL229 are owned by Eni Norge (operator) with 65% and Statoil with 35%.
Goliat main reservoirs of oil and gas
Goliat has two separate main reservoirs - the Kobbe and Realgrunnen - and contains oil with an overlying gas cap.
The Realgrunnen reservoir is situated 1,000m below sea level and the Kobbe reservoir 1,800m below sea level. There are also minor oil discoveries in the Snadd and Klappmyss formations.
The reservoirs are characterised by low pressures - 123bar from Realgrunnen and 192bar for Kobbe. This presents potential challenges for production flow.
Production from the field is expected to start by 2013. Gas from the field will be injected into the Kobbe reservoir or transported to Melkoya.
It is expected that the maximum volume of gas production and reinjection will be 1.3 billion cubic metres a year and will occur a year after production commences.
The field is expected to be in production for up to 15 years, but field life may extend with new discoveries.
FPSO from Sevan / Aker
Eni has two potential development strategies and has signed letters of intent with Sevan marine and Aker Engineering and Technology for preliminary work for a Goliat FPSO, after which Eni evaluated the proposed solutions. The recommendation was based on several criteria, including the environment, for example, the lowest energy consumption and possible electrification from shore.
The Goliat platform will be equipped with a gas turbine with heat recovery and recycling to provide the necessary process heat. The electric cable from shore will be dimensioned to allow for an increase in energy supply.
There must be a low risk of impact in the event of accidental spills and economics (there has to be high recovery and efficient reservoir drainage). The technological solutions have to be designed with a view to cold icing and darkness.
Preliminary front-end engineering design work has begun on the production templates and the flowlines / risers / installation. The development proposal was put to the Norwegian Parliament and approved in May 2009.
The approved development plan includes subsea wells tied to an FPSO. After a thorough evaluation, the Sevan 1000 concept was chosen. Production is expected to be 100,000bopd, including gas.
As per the contract, Sevan Marine will provide project and engineering management and preliminary service for developing the FPSO for the project.
In January 2010, the company signed another letter of intent with Esvagt for ensuring the safe delivery and standby of a vessel to be used for operation during the project.
The vessel will be based on advanced technology to respond immediately in case of oil spill over the project. In February 2010, Eni awarded the EPC contract for the Goliat FPSO to Hyundai Heavy Industries. The contract is worth $1.16bn and includes onshore commissioning and transportation of the FPSO to the field.
In November 2011, the Offshore Division of Lankhorst Ropes was contracted to supply mooring lines for the Goliat FPSO by early 2013.
The FPSO will receive power from a new shoreside power supply system at Hyggevatn in Hammerfest, Norway. The power supply system will comprise a substation at Hyggevatn, overhead transmission lines, a buried cable and an advanced reactive-power compensation system.
The new system is expected to come online in 2012. Powering the FPSO from land will reduce carbon dioxide emissions by half, compared with onboard gas turbines and generators.
Goliat contracts awarded
The EPC contract of a subsea production system for the project was awarded to Aker Solutions in September 2009. The contract is valued at NOK2.3bn and is expected to be executed by 2013.
Under the contract, Aker will provide eight integrated templates, 24 subsea trees, subsea control systems, steel tube umbilicals and workover systems.
A contract for the installation and connection of the flowlines and riser systems was awarded to Technip Norge in October 2009. The scope of the contract includes engineering, procurement and installation of all flowlines and risers. In addition, subsea templates and manifolds, riser bases and umbilicals will be installed. The contract is valued at NOK1.7bn.
In February 2010, CB&I was subcontracted by Hyundai for $50m to provide engineering services for the topside, utility and other modules of the Goliat FPSO.
Aker was awarded a contract in July 2010 to supply a mooring system for the FPSO. Under the $24m contract Aker will supply 14 chain stoppers and three windlasses with a chain size of 165mm. The equipment was delivered in the fourth quarter of 2011. In July 2010, APL was awarded a contract for providing the offloading system for the FPSO.
Technip subcontracted Aker Solutions in November 2010 to provide heating systems for the subsea equipment. Aker was awarded another $10.8m contract in December 2010 to provide tie-in and connector services for the flowlines and risers to be supplied by Technip. Installation works are expected to start in the second quarter of 2013.
In December 2010, Siemens won a contract to build the shoreside power supply system for the field.
ABB also subcontracted Aker for $12m in February 2011 for the installation of a subsea power cable at the field. The 1,065km-long cable, weighing 6,000t, will run from the Hammerfest substation to the Goliat FPSO. ABB was awarded the $110m contract in April 2010.
In February 2011, AGR Field Operations won a contract to provide maintenance and inspection services for the Goliat FPSO.
In April 2011, SAL completed the transportation, loading and discharge of eight drilling templates for the field.
AGR Drilling Services was awarded a contract in June 2011 to deploy its cutting transportation system (CTS) to drill 22 wells at the field. The contract is for a period of four years with an option for a one year extension. The 22 wells will be drilled by the Scarabeo 8 semi-submersible rig.
Hyundai subcontracted Hamworthy in June 2011 to supply an inert gas generator system for the FPSO. Delivery of the system is expected to take place in 2012.