Page 19: of Offshore Engineer Magazine (Nov/Dec 2013)

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Analysis in the UKCS, according to the UK conference, organized by Oil & Gas UK A scientifcally independent research

Government. A Royal Academy of and Decom North Sea. initiative, Insight, has now been

Engineering report in 2012 says 31 of “A number of steel structures rang- launched to address this, added Borwell. those have large steel jackets weighing ing from 4000-20,000-tonne have been

International more than 10,000-tonne, and eight have approved for fabrication and many of large concrete substructures. these are expected to be ready for pro- Outside the Gulf of Mexico and the North

According to a survey of 27 UK North duction before 2017, so competition for Sea, there are only potential markets,

Sea operators (representing 87% of heavy lift vessels is expected to be high in places like West Africa, Middle East, basin activity) by Oil and Gas UK, about also, although fexibility in decommis- India, south Asia, and southeast Asia, £10.4billion will be spent on decommis- sioning is expected to alleviate this.” says Bryd.

sioning over the next 10 years, peaking Capacity for onshore disposal, with “There are thousands of wells that 2015-2019—a period later than the previ- 405,000-tonne expected to land on shore have been suspended and dozens, if not ous year’s survey predictions. in the next 10 years, is thought to exist, hundreds, of platforms currently idle,

This will include 2300km of pipelines, but it has yet to be tested on management particularly in places like the Gulf of infrastructure in 74 felds, 800 wells, of materials, according to a Decom North Thailand,” he says. “The problem in the more than 70 subsea projects and more Sea study. broader international market is the lack than 130 installations, says the report, A further capacity constraint is for of clear and frm regulations. released at the St Andrews conference. rigs, already in demand for production, “This is an issue that is evolving,

The majority of the cost, 44%, will be exploration and appraisal well drilling, particularly in southeast Asia. A group of in the deeper, harsher northern North associated services and human resources. Asian countries recently adopted a broad

Sea, with 32% in the central North Sea The UK industry is also behind the outline for decommissioning regulations, and 24% in the southern North Sea and Gulf of Mexico in understanding the lon- but they have not been implemented.

Irish Sea. ger term effects of offshore installations This is standing in the way of seeing a lot

Most of the cost, 43%, is expected to on the North Sea eco-system. of actual decommissioning taking place. be spent on plugging and abandoning “Through JIPs and work with Decom “The other impediment, and perhaps (P&A), with a further 21% on removal North Sea, there is a realization we don’t an even more diffcult issue to resolve, and 19% on overheads. The remaining know much about the interaction of instal- is the national oil companies, who cost will be on topsides preparation and lations with the North Sea eco system,” are generally involved very heavily in making safe facilities and pipelines. says Mick Borwell, Oil & Gas UK’s envi- places like Indonesia, and to some extent

Average costs of well P&A in the ronmental issues director. “The Gulf of Malaysia and Thailand, are very reluctant northern and central North Sea, based Mexico does, but the North Sea is differ- to spend the money required on decom- on current spending, were estimated ent. We need to acquire new knowledge.” missioning.” as £4.7 million for a platform well, £8 million for a subsea exploration

The Murchison and appraisal well, and platform is in Block 211/19, £10.1million for subsea northern North Sea in 156m development wells.

water depth. First production

In the southern North was in 1980.

Sea and Irish Sea, average costs were estimated as

It stands on an 8-legged steel £3.5 million for a platform jacket, weighing 24,640-tonne, well and £6.6 million for excluding piles. It is a candidate subsea wells, of which for OSPAR derogation, which there are fewer. means part of the jacket could

The limitations in the be left in place.

North Sea are seen to

The topsides comprise 26 be not having enough modules, weighing 24,584- heavy lift vessels with tonne. It has 34 wells, one the capacity to lift and of which is subsea. It also remove the tonnage has subsea infrastructure. expected.

Murchison’s total height is 254m “If we look at the (833ft). limited number of suc-

Aker Solutions was recently cessfully decommis- awarded a three year contract sioned platforms to date, for the engineering design, removal has been limited procurement and ofshore to below 5000-tonne,” execution to prepare the says Abigail Clark, facilities for removal. analyst at Oil & Gas UK,

CNR’s central North Sea

The estimated landing to shore also speaking at the

Murchison platform.

of material period is 2015-2021. oedigital.com November 2013 | OE 21 019_OE1113_ Analysis.indd 21 10/28/13 1:23 AM