Gina Krog (formerly Dagny) oil and gas field is located in Blocks 15/5 and 15/6 of production licenses (PL) 303, PL 048, PL 029C and PL 029B of the North Sea, Norway. It lies in water depth of 120m about 10km away from the Sleipner West field.
PL 303 is 100% owned and operated by Statoil. It is also the operator of PL048 and holds a 78.2% stake with Total holding the remaining interest. PL 029 is 100% owned and operated by ExxonMobil Exploration and Production Norway. Partners in PL 029B include Statoil (50%), ExxonMobil (30%) and Det Norske (20%).
Statoil plans to develop Gina Krog along with the Eirin gas and condensate field located 9km away in PL 048E. The provisional shares in the project are Statoil (operator) 58.7%, Total (38%) and Det Norske (3.3%).
An investment of NOK 31bn (approximately $4.7bn) is expected to be made in the development. Statoil submitted the plan for development and operation (PDO) for the field to The Norwegian parliament (Storting) in December 2012 and the PDO was approved in May 2013.
First production from the project is expected in the first quarter of 2017 and the fields are expected to continue production till 2037.
Discovery of the Gina Krog oil and gas field
Gina Krog was discovered by the 15/5-1 well in 1974 and was considered to be a small gas field. Eirin was discovered in 1978 by the 15/5-2 well.
In 2007, drilling of an appraisal well 15/6-9 S led to the discovery of the Gina Krog East or Ermintrude field. Following this discovery the area around the Gina Krog field was reassessed.
A second appraisal well, 15/5-7, was drilled in 2008 by the Transocean Winner rig. The well led to the discovery of a 100m long oil column below the gas field in the Triassic Skagerrak formation.
Additional appraisal wells, 15/6-11 S and 15/6-11 A, were drilled by the Ocean Vanguard rig to a depth of 4,099m and 3,830m respectively. The wells were drilled four to five kilometres southeast of the 15/5-1 well. The 15/6-11 S well encountered non-mobile hydrocarbons in the Hugin formation and 15/6-11 A encountered a 30m gas column, also in the Hugin formation.
The 15/6-11 A well flowed at a maximum rate of 225,000m ³/d of gas and 120m ³/d of condensate. The two wells provided geological and technical reservoir data required for the development of the field.
The appraisal activities conducted between 2008 and 2011 established the size of the Gina Krog field and also proved that Gina Krog and Gina Krog East are connected. Gina Krog and Gina Krog East have similar pressures and are part of the same structure.
Discovery of the Gina Krog field confirmed that existing areas, such as Sleipner, can still hold large volumes of hydrocarbon reserves.
Geology and reserves of Statoil’s North Sea oil and gas field
The Gina Krog reservoir is of the Upper Jurassic Hugin formation located at a depth of 3,700m. Gas and condensate in the Eirin field is found in the Upper Triassic Skagerrak formation located at a depth of about 4,120m.
The gross recoverable reserves from the project are estimated at 225 million barrels of oil equivalent. Peak production from the project is estimated at 60,000 barrels of oil per day and nine million cubic metres of gas per day.
Field development and contracts awarded for Gina Krog’s development
Gina Krog is planned to be developed through a 16,000t fixed wellhead platform. A subsea production installation including two wells will produce the Eirin field. The installation will be tied back to the Gina Krog platform.
Gas produced at the field will be sent for processing through a tie back to the Sleipner East field. Produced oil will be offloaded onto oil tankers.
Development of Gina Krog will enable the use of spare capacity of the infrastructure at the Sleipner East field. It will also boost the life of the infrastructure.
Aibel has been contracted to carry out the front end engineering design study for the Gina Krog platform.
The contract is valued at NOK80m. Apply Leirvik has been subcontracted by Aibel to design the living quarters for the platform.