Tie-in deals

person By Håkon Lavik, former Statoil employee
A number of agreements exist for the tie-in of other fields to Statfjord. No such contract applies to Statfjord North, however, since clause 22 in the unitisation agreement includes those fields which lie entirely within the original licence.
— Statfjord area with tie-in fields. Illustration: Equinor
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Statfjord East

Statfjord Øst i produksjon, forsidebilde, illustrasjon, Tilknytningsavtaler
Statfjord Øst connected to Statfjord C. Illustration: Equinor

The Statfjord East satellite has a separate tie-in agreement, which was entered into in June 1991. This field has been unitised and accordingly forms a separate legal entity.  The Agreement for Processing of Statfjord East Petroleum and Operation of the Statfjord East Facilities became operative on 1 October 1994, and regulates operation of this field.  A contract to which the Statfjord Unit is not actually a party, but which is significant in this context, is the unitisation agreement for Statfjord East, which makes it possible to produce the field as a single unit.


An agreement was reached in similar fashion with the Sygna Unit. This field is also unitised, with 55 per cent lying in production licence 037 and the rest in PL 089.

Produksjonsstart Sygna, forsidebilde, historie, Statfjord subsea, Tilknytningsavtaler
Sygna field plan. Illustration: Equinor

In addition to the Sygna unitisation accord, to which the Statfjord Unit is not a party, an Agreement for Tie-in and Processing of Sygna Wellstream at the Statfjord Facilities and Operations of the Sygna Facilities, also had to be entered into. Dated 16 December 1998, this makes it possible to produce, process and ship out Sygna reserves via Statfjord.

A complication arose with this field. The bridging agreement does not mention Sygna, quite simply because it did not “exist” in 1991. When work began on the field in 1997-98, the Norwegian licensees wanted to use the provisions in the unitisation agreement on the right to utilise the Statfjord facilities, as with Statfjord East and North. Since only 55 per cent of Sygna lies in PL 037, the British partners initially opposed this. A bitter conflict arose before it became clear that Sygna could be tied back to and produced from Statfjord C.

The solution was that PL 037 would pay a fee of a few US cents per barrel to the Statfjord Unit. Since the UK licensees held 14.53 per cent of the unitised field, they received this percentage of the fee. Sygna could thereby also be tied back to and operated from Statfjord.

Entitled Agreement relating to the Unitisation and Operation of the Sygna Field in Blocks 33/9 and 34/7 and   dated 16 December 1998, the unitisation settlement for Sygna creates the legal entity which operates that field. It does not involve Statfjord, which is only a party to the tie-in contract mentioned above.


Snorre tie-in, Tilknytningsavtaler
Illustration of the tension leg platform for the Snorre field. Illustration: Equinor

Another and rather different settlement preceded the satellite field contracts: the Agreement of Processing, Storage and Onwards Transportation of Snorre Crude Oil and Gas at the Statfjord Facilities. Dated 20 November 1987, this covers “second stage” separation of the oil after the wellstream has been dewatered on the Snorre A platform. The latter began production on 2 August 1992, with its output processed on Statfjord A. The tie-in agreement currently runs until 21 December 2012 (Note! The article is several years old).

In order to tie Snorre back to Statfjord, an Agreement for Tie-in Operation of Snorre Pipelines and Installation of Incremental Equipment at the Statfjord Receiving Platform had to be entered into on 20 November 1987. This specified what was to be installed and which modifications were to be made on Snorre A. The agreement related only to the construction period and is without practical significance today.

When Snorre B came to be installed, however, an additional Agreement for Tie-in of the Snorre B Pipeline and Installation of Incremental Equipment at the Statfjord B Platform was signed on 9 June 1998.

Well from Statfjord C to Statfjord East

In order to improve recovery from Statfjord East by drilling an additional well tied into Statfjord C, an Agreement for drilling of Statfjord East C-33 well and the tie-in of the well to the Statfjord C platform was entered into on 5 August 2004.


The Barnacle Accumulation Royalty Agreement is dated 10 June 2004. It relates to a small UK field located between Brent and Statfjord, where a small section lies within the Statfjord Unit area. The latter accordingly owns part of Barnacle and receives a proportionate share of revenues from its production.


A subsea template is lowered to the Vigdis field. Photo: André Osmundsen/Equinor

The Vigdis field in PL 089 receives certain services from Statfjord. Signed on 4 February 2004, the first accord here was the Agreement for Processing of Vigdis Extension Gas at the Statfjord Facilities , which makes it possible for Vigdis gas to be exported via Snorre A and Statfjord C.

To increase and maintain production from Vigdis, this field receives injection water from Statfjord under the Agreement for the Tie-in of the Vigdis Water Injection Pipeline to Statfjord C and the Provision of Water Injection Services Between the Statfjord Group and the PL 089 Group of 11 October 2007.

An additional agreement was also entered into between Statfjord, Vigdis and Statfjord East for the Statfjord late life project, since this also affects the two other fields. In force from 31 December 2005, the Heads of Agreement between the Statfjord Group and the Statfjord East Group related to the implementation of the Statfjord Late Life Project commits the field units to update their agreements to reflect the effects of the late life project.

Gas from Tordis

The Tiora separation plant is hoisted aboard the Seipem 7000 for transportation to the Tordis field. Photo: Marit Hommedal/Equinor

Tordis is another field in PL 089, which has its output processed on Gullfaks A. For Tordis gas to be exported, the Agreement on Transit of Tordis Gas at the Statfjord Facilities was entered into on 6 September 1993. This agreement was terminated after Gullfaks acquired a new gas export solution.

Gas storage

So that Statfjord North and East could produce as straightforwardly as possible and to cover the possibility that they were unable to export associated gas every day, a gas storage/modulation agreement was entered into. Modulation means that they have their gas delivered when they request it.

The Agreement for Storage of Gas between the Statfjord East and the Statfjord Group based on the Telex Offer of July 1991, which Includes Modulation, draft 17 August 1993 was signed on 1 October 1994. An exactly similar contract with Statfjord North was entered into on the same day.

These agreements have had little practical significance, since the gas was sold under the Troll commercial model, but they provided a production guarantee and opportunities for oil output in the 1994-95 start-up phase.

Published October 31, 2019   •   Updated February 12, 2020
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