OFFSHORE EUROPE
Jeremy Beckman • London
UKCS decommissioning predicted to rise
Over the next 10 years, 65% of the UK’s producing offshore fields look set to be decommissioned, according to a study by Deloitte and analysts Douglas Westwood. These fields support 45% of the sector’s steel platforms and over two-thirds of its subsea facilities.
The report, presented at a recent conference in Aberdeen, also identified constraints for the industry in the UK when entering the decommissioning phase, including potential bottlenecks in the supply chain and a lack of suitable onshore disposal facilities.
One major project undertaken in stages in 2008-09 involved removing the 20,000-ton (18,143-metric ton) topsides and 17,500-ton (15,876-metric ton) jacket from the North West Hutton field, which BP shut down in 2002. This work was managed by Heerema, with all removed structures subsequently transported to Able’s recycling/disposal plant at Teesside, northern England.
Last year, BP decided to offer the field for redevelopment, and recently reached an accord under which Fairfield Energy will acquire 100% of the surrounding blocks 211/27a and 211/27c. Following a detailed subsurface study of North West Hutton and its remaining oil, Fairfield plans to install subsea facilities, tied back 25 km (15.5 mi) to its Dunlin A platform.
StatoilHydro planning for the future
StatoilHydro is gearing up for a major overhaul of some of its heavyweight North Sea production centers. Among various newly announced programs, the company has contracted Aker Solutions for a front-end engineering design (FEED) study to upgrade the drilling facilities on the Gullfaks A platform. One proposal involves installing equipment to raise drilling capacity, including a new derrick that would potentially extend drilling reach to 10 km (6.2 mi).
Another Norwegian contractor, Aibel, was awarded three studies. One is conceptual work for two further compressor trains for the Troll A platform, including power supply needs, to cater for a future phase of development on the Troll gas field. Another is FEED work on upgrading the drilling facilities on Oseberg A in cooperation with the drilling operator KCA Deutag. Additionally, Aibel was handed the topsides FEED contract for a proposed wellhead platform on StatoilHydro’s gas/condensate Valemon field close to Gullfaks and Kvitebjorn.
Drilling focus switches to Shetland
Another Deloitte survey, the “North West Europe Review,” suggests that exploration and appraisal drilling across the UK shelf rose by 75% in 3Q 2009 compared with the previous three months. A total of 28 wells were spudded, with 32% West of Shetland, a region that normally accounts for only 10% of the UK total.
The impetus is partly due to the rolling program of the deepwater drillshipStena Carron, which led last month to a discovery in the Tornado prospect for OMV (UK). The well, drilled 30 km (18.6 mi) northwest of BP’s producing Schiehallion and Foinaven fields in block 204/13, found oil and gas in Tertiary reservoir sandstones in a water depth of 1,048 m (3,438 ft). The partners planned a sidetrack to delineate the find, and to determine its size and fluid types.
Earlier, the Dong-led partnership on license P1195 confirmed a “high quality” gas find in the same region following a side track on the Glenlivet discovery, drilled by the semisubTransocean Rather in 1,430 ft (436 m) of water.
Studies to assess Jan Mayen potential
Norway’s government is considering opening the Jan Mayen region between the Norwegian Sea and Greenland for exploration. As a first step, the Petroleum and Energy Ministry will perform an impact assessment of petroleum activities in this area, while the Norwegian Petroleum Directorate (NPD) will cooperate in mapping the area’s petroleum resources base.
Current information is extremely patchy, according to NPD’s exploration director, Sissel Eriksen. “We have some seismic data already, but the distance between the lines is far too great.” The area around Jan Mayen is known to contain both source rocks and reservoir rocks, she says, which are probably similar to those encountered in the Mid-Norwegian Haltenbanken region.
Basalt overlying the geological strata could present imaging difficulties, she adds. Otherwise, although water depths are deep – between 1,000-2,000 m (3,281-6,561 ft) – the prevailing weather is generally temperate, with lower wave heights than those encountered off Norway’s western coast.
DONG addresses Siri cracks
DONG was aiming to restart production from its Siri field in the Danish sector this month, following an enforced shutdown at the end of August. A routine inspection of the Siri platform had revealed cracks in a subsea structure connected to the oil storage tank at the platform’s base. That structure carries the load of the caisson containing risers and conductors.
The problem was traced to failure of the grouting material designed to fix the caisson. DONG has applied a temporary solution which involves connecting a drilling jackup to the caisson.