Decommissioning - Industrial Cleaning

Scope of Work

Stork was contracted to carry out full topside industrial cleaning and decontamination on-board a floating production storage and offloading asset (FPSO) within the North Sea.

The scope of work included the decontamination of all production vessels, cargo tanks and pipework. It required the removal of substantial quantities of hydrocarbon, naturally occurring radioactive material (NORM) and contaminated waste.

Stork's Approach

Through the efficient mobilisation of a 10-man multi-disciplined team, working a range of shifts, our experts safely carried out confined space entry cleaning utilising a variety of high pressure water jetting techniques to ensure effective waste removal. Thereafter, deploying our sand washing system (SWS) to provide a safe, efficient and environmentally friendly method for sand removal and treatment.

This significantly reduced the logistical and financial burden associated with onshore waste treatment and disposal for the client.

The Outcome

• All work was carried out with a safety-first approach with no accidents, incidents or injuries reported.
• The workscope was completed in 43 days, undertaking 4,440 man-hours.
• A recorded total of 30,11tonnes (30,110kgs) of NORM contaminated solids waste were removed from the vessels and tanks by man-entry under Full Breathing Apparatus (BA).
• The removed contaminated sand waste was subsequently cleaned, analysed and discharged safely overboard with the sand analysis results showing an average of 0.038% (382.213 mg/kg) oil sand content achieved, which is below legal environmental requirements.
• Cleaning the contaminated sands on site, eliminated the need to skip and ship the waste for onshore disposal which would have likely involved the waste being sent for incineration. As a result approximately 750kg CO2e was estimated to have been avoided.