Shell announced yesterday that decommissioning its now mostly ‘dry’ and non-operational iconic Brent field would take up to 10 years because the ‘sheer scale and age of the field’, the complex infrastructure, and the engineering challenges of how to decommission the concrete legs and cells, and the cell contents.
In fact, it is so complex and potentially difficult to dismantle and decommission the 40-plus-year old structure, that Shell may simply abandon the steel and concrete platform bases on the sea-bed by seeking a special exemption** from the international OSPAR convention that otherwise stipulates total – onshore – decommissioning.
Only one Brent platform is still operating and its remaining economic lifespan is limited. The Brent field infrastructure is extensive and comprises:
- Four topsides (the Brent A, B, C and D platforms) with a combined weight of over 100,000 tonnes
- Three gravity based structures weighing more than 300,000 tonnes each
- 31,500 tonnes of steel jacket and more than 100km of pipelines.
A spokesman for Shell – which yesterday published its latest annual waste, environment and decommissioning annual report – said: “The decommissioning of the Brent field and facilities is one of the most significant decommissioning projects in the North Sea and is likely to span well over a decade.
“However, within both the UK and OSPAR regulatory framework it is recognised that there may be particular difficulties associated with the removal of large steel structures or the gravity bases of concrete platforms. In such situations operators are able to make a case for exemption** from the general rule of complete removal, known as a ‘derogation’.”
The Brent field was a prolific national asset and has created and sustained thousands of jobs across the UK and – since 1976 – has produced around three billion barrels of oil equivalent. At its peak it was producing more than half a million barrels a day. During this time, it has also generated around £20 billion of tax revenue.
The latest annual Waste, Environment and Decommissioning reports which Shell – and all 33 other N. Sea oil field operators – have to produce were published yesterday by Brit-Govt. These comprise:
Alpha Petroleum, BP, Centrica Energy, Centrica Storage, Chevron, CNR, Conoco, DANA, ENGI, Eni Hewett, ENI UK, Enquest, EOG, Fairfield, Faroe, INEOS, IOG, Ithaca, JX Nippon, Maersk, Marathon, NEXEN, ONE, Perenco, Petrofac, Premier Oil, Repsol Sinopec, Shell, Statoil, TAQA, Total, Verus, Wintershall and Zennor:
The Shell and other N. Sea operator annual reports can be viewed in full here:
20 Sept 2017