The Snorre B Project: Main factors contributing to the success
Authors: Birkeland Vidar , Kviljo Karstein , Brustad Halfdan , Aasgaard Gabriel 
Published: October 2008

This paper gives a summary of the Snorre B field development project in the Norwegian sector of the North Sea. The paper will include project execution and contract strategy descriptions and experiences throughout the project. The main factors contributing to the main results will be discussed. Further a brief description of the Concept and field development requirements will be included.

The Operator of the Snorre field is Norsk Hydro with the following partners: Den Norske Stats oljeselskap (Statoil) Exxon Mobil, TotalFinaElf, Idemitsu, Amerada Hess, RWEDEA and Enterprise oil.

Concept description and field requirements

The field is located in the Tampen area in the Norwegian sector of the North Sea located approximately 150 kilometers West of the Norwegian coast. The Snorre Field covers block 34/4 and block 34/7. The Snorre South field has been developed with a Tension Leg Platform (TLP) and a subsea production system. The Snorre TLP started production in 1992, and exports partly processed oil via pipeline to Statfjord A for final processing and offloading. Gas is partly exported and partly reinjected into the reservoir to increase oil recovery.

During the Snorre TLP field development two possible scenarios for the Snorre northern region (Snorre B) were considered; the installation of two additional subsea production systems or move the TLP to the northern region. Due to discovery of increased reserves in the Snorre area, a new scenario including a floating production unit was introduced.

During concept selection in 1997 a Semisubmersible production platform (SSPV) was chosen.

The Snorre B field has been developed with a Semisubmersible platform with drilling, full processing, utility and living quarter (LQ), and a subsea production system with a total of 26 production and injection wells connected to the SSPV via flexible risers. The fully processed oil is exported to Statfjord B for storage and offloading. The gas is reinjected into the reservoir utilizing the water alternating gas technique (WAG) or exported via pipeline to Snorre TLP for transport through the Statpipe system.

The water depth is 345 meter.

Main functional requirements are listed below:Oil production 18000 Sm3/dayTotal liquid 28000 Sm3/dayProduced water treatment 15000 Sm3/dayWater injection 25000 Sm3/dayGas injection 3x10*6 Sm3/dayProduction pressure 250 barInjection pressure 345 barProduction wells 16Injection wells (W AG) 10

In order to reduce discharges to the environment, the following systems were incorporated:Injection of produced waterInjection of drill-cuttingsWaste heat recovery unit with steam plant of 15 MWHigh voltage power cable between Snorre TLP and Snorre B for optimized field power generationDownhole production control system

The Snorre B SSPV concept is an Aker Maritime design with integrated deck and a layout philosophy as follows; Living quarter-Utility area-Drilling and Mud area- and Process area with the gas processing and oil separation modules located on top of the platform.