Development concept decided for the Johan Sverdrup field

This article originates from the news archive of Det norske.

13. February 2014

The partners in the Johan Sverdrup field have decided a development concept for Phase 1. The giant field will start producing in 2019, and is one of the largest fields ever on the Norwegian shelf. The anticipated life of the field is 50 years.Øyvind Bratsberg, Chief Operating Officer of Det norske, says that the concept selected for the development of the Johan Sverdrup field is good and robust.

– This is a unique field and one that will create significant value for society. Field production will represent approximately a quarter of all Norwegian oil production once it has reached plateau production. We are proud to participate in this development.

Development concept

The field centre in the first phase will consist of a processing platform, drilling platform, riser platform, and living quarters. Illustration: Statoil.

The resource estimate for the Johan Sverdrup field is between 1.8 to 2.9 billion barrels of oil. The field will be developed in several phases. The first phase is forecast to have a production capacity of between 315,000 and 380,000 barrels of oil equivalents per day. Pre-drilling of wells will contribute to a rapid production ramp-up. More than 70 per cent of the total resources in the field can be produced with the facilities installed in the first phase.

 

All included
Investment in the first phase is estimated at between NOK 100 and 120 billion. This includes the entire field centre, wells, export of oil and gas, and power supply. The estimate also includes contingencies and allowances for market adjustments. In addition, the first phase will facilitate capacity for enhanced oil recovery measures, says Øyvind Bratsberg.

– Det norske is of the opinion that it is possible to increase the recovery factor significantly; up to 70 per cent.

The partnership works continuously to lower the level of investment in the first phase.

Large capacity
The field centre in the first phase will consist of a processing platform, drilling platform, riser platform, and living quarters, and has been designed so as to facilitate capacity for future development. The platforms are installed on steel jackets linked by bridges. They will be installed at a water depth of approximately 120 metres.

The field centre

The field centre for the Johan Sverdrup field in the first phase will consist of four installations. Illustration: Statoil.

The field centre in the first phase is robust and flexible. Future development phases shall ensure good utilisation of the areas that constitute the Johan Sverdrup field. For future phases, a number of concept selection decisions will be made before the final field development concept is in place. Fully developed, the field is anticipated to reach a plateau production of 550,000 to 650,000 barrels of oil equivalents from the entire field. From both a technical and an economic perspective, the expected life of the Johan Sverdrup field is approximately 50 years.

New infrastructure
The export solution for oil and gas from the Johan Sverdrup field is transportation to shore via dedicated pipelines. The oil will be transported to the Mongstad terminal in the county of Hordaland. The gas will be transported via the Statpipe system to Kårstø in the county of Rogaland for processing and onward transportation. Johan Sverdrup Phase 1 will be supplied with power from shore, with a converter at Kårstø supplying direct current to a converter on the riser platform, ensuring a 80 megawatt supply to the field centre.

The partnership
The Johan Sverdrup field consists of three production licences. Det norske has a 20 per cent interest in PL 265 and a 22.22 per cent interest in PL 502. Partners in PL 265 are Statoil 40 per cent (operator), Petoro 30 per cent, and Lundin Norway with a 10 per cent interest. PL 502 partners are Statoil, with a 44.44 per cent interest (operator), and Petoro with a 33.33 per cent interest. Lundin Norway has a 40 per cent interest in PL 501 (operator), Statoil has a 40 per cent interest, and Maersk Oil holds a 20 per cent interest.

SignatureFacts about the Johan Sverdrup field (PL 265, PL 501, PL502)

The field centre for the Johan Sverdrup field in the first phase will consist of four installations. They are installed on steel jackets and will be linked by bridges. The water depth is approximately 120 metres.

Process platform

Has all the processing capacity for the entire field centre in Phase 1. Separation and injection systems. Gas, oil and injection water are transported by pipeline to a riser platform. Designed for a capacity of 315,000 barrels of oil equivalents, but might process up to 380,000 barrels of oil equivalents.  The platform deck has three modules with two separation trains for oil and gas separation, cleaning of produced water, gas treatment and utility systems. Supported by an eight-leg steel jacket. The platform deck is 100 metres long and 23 metres wide, and the weight is estimated at 23,000 tonnes.

Drilling platform

The field centre is planned developed with an integrated drilling facility. This concept was selected on the basis of seabed conditions and the number of wells from the field centre. The platform deck consists of 48 slots, well intervention deck and manifolds. Supported by an eight-leg steel jacket. Predrilling is performed by a semi-submersible drilling rig through a predrilling template. The estimated weight is 15,000 tonnes dry weight. Size: 40 metres x 83 metres.

Riser platform

This is the centre for export of processed oil and gas, as well as the centre for incoming volumes from future tie-backs from satellite fields.  The platform is designed with between 40 to 50 risers and J-tubes. Water injection and oil export pumps are also localised here. The platform has a converter module (DC/AC) for power from shore. In the first phase, the platform consists of three modules. Large sections of the weather decks on these modules have been designed so as to enable future installation of EOR (enhanced oil recovery) modules and/or handle increased production from future development phases. The dry weight of the platform deck is approximately 19,000 tonnes in the first phase and is ca. 125 metres long and 30 metres wide.

Living quarter

The platform deck consists of the living quarter itself, with 450 cabins, control room and utility/control system. The helideck and lifeboats are also localised here. The size is 85 x 28 metres, and it is supported by a four-leg steel jacket. The weight is approximately 16,500 tons.

Transport solutions

The oil will be transported to the Mongstad terminal in the county of Hordaland by a 274 km long, 36-inch diameter pipeline. The project includes transportation to shore and alignment and modifications to the Mongstad terminal.

The gas will be transported to Kårstø in the county of Rogaland for processing and onward transportation. The pipeline will be 165 km long, with an 18-inch diameter. It will be tied into the Statpipe system by means of a subsea tie-back (hot tap). The tie-back point is located approximately 10 km west of Karmøy.

The underground

The field contains volumes estimated to between 1.8 to 2.9 billion barrels of oil equivalents for the entire field. The reservoir spans more than 200 square kilometres. The reservoir is at a depth of approximately 1,800 – 1,900 metres below the sea floor. The reservoir properties are very good and characterised by good flow properties. Normal pressure and normal temperature (hydrostatic). Requires pressure support from water injection.