Gullfaks

25.04.2013

Gullfaks 

Blocks and production licences

  • Block 34/10 - production licence 050, awarded 1978
  • Block 34/10 - production licence 050 B, awarded 1995

Development approval: 09.10.1981 by the Storting

Discovered: 1978

On stream: 22.12.1986

Operator: Statoil Petroleum AS

Licensees

  • Petoro AS 30.00 %
  • Statoil Petroleum AS 70.00 %

Recoverable reserves

Original

  • 365.5 million Sm³ oil
  • 23.1 billion Sm³ gas
  • 2.8 million tonnes NGL

Remaining as of 31.12.2012

  • 11.6 million Sm³ oil

Estimated production in 2013

  • Oil: 39 000 barrels/day

Expected investment from 2012: 39.6 billion 2012 values

Total investment as of 31.12.2011: 74.9 billion nominal values

Main supply base: Sotra and Florø

 

Development: Gullfaks is an oil field located in the Tampen area in the northern part of the North Sea. The water depth in the area is 130 – 220 metres. The field has been developed with three integrated processing, drilling and accommodation facilities with concrete bases and steel topsides (Gullfaks A, B and C). Gullfaks B has a simplified processing plant with only first stage separation. Gullfaks A and C receive and process oil and gas from Gullfaks Sør, Gimle and Visund Sør. The facilities are also involved in production and transport from the Tordis, Vigdis and Visund fields. Production from Tordis is processed in a separate facility on Gullfaks C. A PDO for Gullfaks C was approved in June 1985, a PDO for Gullfaks Vest was approved in January 1993, and recovery from the Lunde Formation was approved in November 1995. In December 2005, an amended PDO for the Gullfaks field covering prospects and small discoveries which can be drilled and produced from existing facilities was approved.

Reservoir: The Gullfaks reservoirs consist of Middle Jurassic sandstones of the Brent Group, and Lower Jurassic and Upper Triassic sandstones of the Cook, Statfjord and Lunde Formations. The reservoirs lie at a depth of 1 700 – 2 000 metres. The Gullfaks reservoirs are located in rotated fault blocks in the west and a structural horst in the east, with a highly faulted area in-between.

Recovery strategy: The drive mechanisms are water injection, gas injection and water/alternating gas injection (WAG). The recovery strategy varies between the drainage areas on the field, with water injection as the main strategy.

Transport: Oil is exported from Gullfaks A and Gullfaks C via loading buoys onto tankers. Rich gas is transported through Statpipe for further processing at Kårstø.

Status: Evaluation of lifetime extension of Gullfaks is ongoing. This includes upgrades to the drilling facilities. Increased oil recovery through optimized distribution of gas and water injection in the various areas of the field is a major challenge. The licensees are also evaluating injection of silica gel as a method to increase oil recovery from Gullfaks. Studies are ongoing on future tie-in of Snorre oil export. Future tie-in of export oil from Snorre is being studied.

 

Production - Gullfaks