Statfjord late life is a commercially marginal project which calls for substantial reorganisation and efficiency improvements.
Executing it will be very challenging. Statfjord B and C need substantial upgrading to produce gas. The A installation is already equipped for low-pressure output, and its adaptations and well programme will both be limited.
Modifications will be carried out while all three platforms are in full operation and without disrupting production to any extent. At the same time, safety levels must be maintained.
The limited amount of planned prefabrication means that most of the work will be done offshore, amounting to about three million hours over at least four years.
In addition come about three million engineering hours on land as well as some prefabrication.
Well programme
Covering more than 55 of the 124 existing wells on the field, the well programme includes drilling sidetracks and re-completing for installing gas lift and sand control equipment.
Processing facilities will be modified to accept gas at lower pressure and debottlenecked, and have their health, safety and environmental standard and technical condition enhanced.
The well programme will run until 2013.
Modifications in three phases
Modifications will be pursued in three phases. This will embrace installation of gas lift and sand control in a number of wells as well as upgrading of topside HSE standards and technical condition, including in the drilling facilities.
Phase two is running from the autumn of 2007 to the end of 2009. In this phase the production equipment is being converted so that it can receive and handle production of oil and gas with lower pressure, at the same time as the drilling programme is underway.
Phase three, which will run from 2010 to 2013, includes the installation of downhole pumps in 12 wells at Statfjord B and C, with associated equipment on the platform for electricity supply and reception of the well flow. The purpose of these wells is to accelerate pressure reduction in the reservoir in order to release more gas.
The production estimates are roughly 32 billion cubic metres of gas, 25 million barrels of extra oil and eight million tonnes of condensate (natural gas liquids - NGL) over and above the expected volume produced by using the present recovery strategy.