Oil and gas company Chrysaor is working on a pipeline bypass program in the UK North Sea, following a blockage which forced Chevron to shut-in production from its Erskine field.
The Erskine field lies approximately 150 miles (241 km) east of Aberdeen, in water depths of about 296 feet (90 m). It is operated by Chevron (50 percent) with Chrysaor (32 percent) and Serica Energy (18 percent) as its partners.
The field includes a normally unattended installation, which is remotely controlled from Chrysaor’s Lomond platform. An 18.6 mile (30 km) pipeline links the two facilities.
Last January, during cleaning operations a blockage occurred on the Lomond to Everest pipeline, through which Erskine condensate is exported to market. This caused Erskine field production to be shut-in. The blockage is believed to be due to a deposit of wax in the pipeline.
According to Serica’s statement on Tuesday, Chrysaor, the operator of this pipeline, has been attempting to resolve this problem but has been unable to achieve a significant breakthrough. Therefore, the decision has been made to cease clearance operations and instead concentrate on accelerating the pipeline bypass program and on running an extended maintenance program.
Restart in September
Serica also said that plans to lay a new 26km length of pipeline to bypass the zone affected by wax deposits have been progressing. An order was placed with the pipeline manufacturers in February and a route survey has been completed. Approvals for the work from the authorities are expected in July and construction is scheduled for August, with production restart expected in September. Once laid, a proactive cleaning program will start in order to maintain the pipeline through high frequency pigging.
As a significant maintenance program was already planned for this summer, Chrysaor as the Lomond operator has taken this opportunity to extend this, performing further, pre-emptive maintenance on the platform whilst it is hydrocarbon free. From May 1, work will start to reduce the backlog of maintenance work as well as perform inspections and replace and repair key equipment.
This work is designed to improve future performance of the facilities, reducing production interruptions and reducing the length of future shut-downs in the coming years.