Draugen Oil Field, Norway
The Draugen oil field is operated by Norske Shell, which also owns a 26.20% stake in the field. The remaining stake is held by Petoro (47.88%), BP Norge (18.36%) and Chevron (7.56%). The field lies in block 6407/9 in the Haltenbanken area which is situated about 140km from Kristiansund, Norway. The field lies in production licence PL093.
In a contract estimated to be worth NKr200m ($34.16m), Aker Offshore Partner (a subsidiary of Aker Solutions) will set up a water reinjection system at the Draugen field. The contract was awarded by Shell in December 2009. The contractual scope includes engineering, procurement, construction and installation of the reinjection system. Aker expects to complete the installation by January 2012.
The field was shut down in February 2010 due to cold weather and extreme winds. Shell is yet to resume operations at the facility.
Draugen field discovery and reserves
The field was discovered in 1984 by the first well drilled in the block. The discovery wellbore was a wild cat well designated 6407/9-1.
As of 31 December 2009, the recoverable oil reserves at Draugen stood at 145 million standard cubic meters. The remaining reserves stood at 19.7 million cubic metres.
The Draugen field produces oil primarily from two reservoirs. The main reservoir contains sandstone of Rogn formation, found to be of the late Jurassic age. The other deposit, located in the west, is the Garn formation of middle Jurassic age. The Rogn and Garn deposits are homogeneous and both lie at a depth of 1,650m.
Draugen field development
The Draugen field was initially developed with five subsea wells connected to a central platform. The field currently has six platform wells and eight subsea wells. Of these, 12 are production wells.
Field development has so far included drilling of nine exploration wells and 25 development wells. The first exploration well, 6407/9-1, was a wild cat well drilled in 1984. Four more appraisal wells were drilled in the following year. The sixth appraisal well was drilled in 1986. It was suspended initially, but re-entered later. The last three appraisal wells were drilled in 1993, 1999 and 2003 respectively. Altris supplied document viewing and management software to Shell during the field development.
The Garn reservoir in the west of Draugen was developed with two subsea wells. It began production in late 2001. The Rogn reservoir was developed with two subsea wells in 2002 and production from the reservoir began in November the same year. One further subsea well was drilled in each of these reservoirs in 2007. The new wells at the Garn and Rogn were named D3 and E3 respectively. Production from the two subsea wells commenced in 2008.
The subsea system at Draugen, installed by FMC Technologies, includes two water injection wells, two oil production satellite wells and a gas injection satellite well. The system required nine vertical subsea trees of 5,000psi. The subsea wells were tied to the common Draugen platform.
Acergy installed the flexible pipe and umbilical system at Draugen in 2008. Normand Mermaid and Acergy Eagle ships were used for the marine installations. Acergy installed a 2.3km gas lift and 2.4km production flowlines as part of the contract.
NKT Flexibles will supply two water injection flowlines for subsea installations at the field. Two flexible lines will be supplied, one for reinjection of produced water and another for that of sea water. The installation will be undertaken in mid 2011.
The Draugen platform was installed in 1993. Resting on a single column, the platform consists of a concrete shaft with integrated topside decks. The production capacity of the platform is about 140,000bpd.
Aker Kvaerner is maintaining the platform under a five-year contract signed with Shell in 2005. The contractual agreement has an option to renew the contract every two years after the end of the initial contract period.
The EPC contract for subsea well facilities at the Draugen field was awarded to FMC Technologies in 1990. FMC designed the subsea installations for diverless installation, operation and maintenance.
The marine installation contract for Draugen D3 and E3 development, which included flexible pipe and umbilical system, was given to Acergy in March 2007. Acergy awarded the water injection flowlines supply contract NKT Flexibles in May 2010.
Bjørge Eureka, the Norwegian subsidiary of Bjørge, was awarded a contract in July 2009 to upgrade the generator system at the Draugen platform and supply centrifugal pumps to the platforms.
Shell began producing oil at the Draugen field in October 1993. Use of 4D seismic technology has helped Shell to increase the production life of the Draugen field. The company expects to continue production at the field at least until 2024.
The average crude oil production at the field in 2009 stood at 63,000bpd, a decrease of 14.8% over 2008. Production has been falling continuously since 2004 when the average production stood at 144,000bpd. Various production optimisation initiatives have been undertaken by the company over the years. In order to increase oil recovery and production, the company is planning to add some more wells to the field.
The Garn West reservoir is connected to the Draugen platform by a 3.3km-long pipeline. The pipeline laid via the Garn West reservoir connects the Rogn deposit to the project platform.
While the oil extracted from the field is transferred to a floating loading buoy, the associated gas is transported to processing plant at Karsto by means of the Asgard Transport pipeline.