Decommissioning forecast in the deepwater Gulf of Mexico, 2013–2033

Kaiser, Mark J.

doi:10.1016/j.marstruc.2014.12.006

Cited by 13 publications

(8 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As ageing hydrocarbon fields approach the end of their productive and economic life [63,81,125], and as various options for their potential reuse, such as geological storage of CO 2 [3,50,127] or of energy [8,52,99] emerge, wellbore sealing issues are becoming ever more important [5,19]. In particular, effective plug and wellbore sealing procedures, ensuring long-term zonal isolation, are essential (a) for complying with increasingly stringent environmental regulations applying to well and reservoir abandonment [109] and (b) for enabling reuse of reservoirs in future applications [51].…”

Section: Introductionmentioning

confidence: 99%

Reaction-driven casing expansion: potential for wellbore leakage mitigation

2017

View full text Add to dashboard Cite

It is generally challenging to predict the postabandonment behaviour and integrity of wellbores. Leakage is, moreover, difficult to mitigate, particularly between the steel casing and outer cement sheath. Radially expanding the casing with some form of internal plug, thereby closing annular voids and fractures around it, offers a possible solution to both issues. However, such expansion requires development of substantial internal stresses. Chemical reactions that involve a solid volume increase and produce a force of crystallisation (FoC), such as CaO hydration, offer obvious potential. However, while thermodynamically capable of producing stresses in the GPa range, the maximum stress obtainable by CaO hydration has not been validated or determined experimentally. Here, we report uniaxial compaction/expansion experiments performed in an oedometer-type apparatus on precompacted CaO powder, at 65°C and at atmospheric pore fluid pressure. Using this set-up, the FoC generated during CaO hydration could be measured directly. Our results show FoC-induced stresses reaching up to 153 MPa, with reaction stopping or slowing down before completion. Failure to achieve the GPa stresses predicted by theory is attributed to competition between FoC development and its inhibiting effect on reaction progress. Microstructural observations indicate that reaction-induced stresses shut down pathways for water into the sample, hampering ongoing reaction and limiting the magnitude of stress build-up to the values observed. The results nonetheless point the way to understanding the behaviour of such systems and to finding engineering solutions that may allow large controlled stresses and strains to be achieved in wellbore sealing operations in future.

show abstract

Section: Introductionmentioning

confidence: 99%

Reaction-driven casing expansion: potential for wellbore leakage mitigation

2017

View full text Add to dashboard Cite

show abstract

“…Cutting of the monopile is carried out in various steps based on the cutting stage involved, i.e. external cutting or internal cutting (Kaiser 2015;Smith and Lamont 2017). Internal cutting involves dredging or pumping away the mud to create an execution pit to enable the cutting and removal of the pile.…”

Section: Foundationmentioning

confidence: 99%

“…After this step, it would be possible to cut the monopile and remove it. The pit should be filled with mud again after the execution of the job (Kaiser andSnyder 2012, 2010).…”

Section: Foundationmentioning

confidence: 99%

“…The detached foundation is then loaded onto the chosen transportation vessel and shipped when the vessel has full capacity (Topham and McMillan 2017). Tow cutting may undertake external or internal cut strategies (Kaiser andSnyder 2010, 2012;Kerkvliet and Polatidis 2016). Seabed depth and the possibility of excavation surrounding the seabed are the two main factors impacting the external pile cutting.…”

Section: 121mentioning

confidence: 99%

“…Decommissioning, which is the ultimate end-of-life strategy to be considered for an asset, is defined as the process of disassembling the wind turbine (WT) with a view to returning the site to its preinstallation phase, to the extent this is possible (Kaiser 2015;Topham and McMillan 2017). The first decommissioning of an OWF was done in 2017 to the Vindeby wind farm in Denmark, due to the difficulty in finding spare parts as a result of technology obsolescence and the considerable costs associated with repairs and upgrades after 25 years of operation.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A multi-attribute review toward effective planning of end-of-life strategies for offshore wind farms

Jadali

Ιωάννου

Kolios³

2021

Energy Sources, Part B: Economics, Planning, and Policy

View full text Add to dashboard Cite

With many offshore wind turbines (OWTs) approaching the end of their estimated service life, there is an increasing demand for developing and evaluating end-of-life strategies that can maximize these assets' value while at the same time satisfying the requirements of the stakeholders involved. This study aims to perform a detailed review and develop a framework that will consider multiple criteria in the decision-making process, presenting and discussing available technologies and strategies, as well as influencing factors such as schedule, cost and environmental impact. Service life extension, repowering and decommissioning are included in this review as the main end-of-life strategies considered by asset owners, and these are translated into four processes that are applicable to offshore wind farms through a generic decision tree. A SWOT analysis is also conducted which aims to compare the different characteristics of the proposed processes. The factors contributing to the uncertainty of the processes as well as lessons learnt from the oil & gas industry are also discussed.

show abstract

Decommissioning vs. repowering of offshore wind farms—a techno-economic assessment

Jadali

Ιωάννου

Salonitis

et al. 2021

Int J Adv Manuf Technol

View full text Add to dashboard Cite

Offshore wind turbines are normally designed for a nominal service life of 20 to 25 years; however, with a significant number of units approaching the second half of their service life, the discussion on selecting the most appropriate end of life scenario becomes ever more relevant. Scenarios to be investigated mainly include decommissioning, repowering or service life extension, while such decisions depend on a number of criteria which should be taken into account and should ultimately inform a techno-economic and risk assessment. This paper performs an initial comparative assessment between two of these scenarios, repowering and decommissioning, through a purpose developed techno-economic analysis model which calculates relevant key performance indicators. The economic model of risk aversion is further adopted to calculate the certainty equivalent of LCoE (Levelized Cost of Energy) based on each of the examined end of life scenarios and a stochastic expansion of the deterministic model. An application to a typical, hypothetical offshore wind farm, qualifies the full repowering scenario as the prevailing option, under the assumptions considered, with a lower amount of risk premium (1.136 £/MWh) and certainty equivalent (69.821 £/MWh) in comparison to other scenarios, reducing LCoE by nearly 35% compared to partial decommissioning and 36.5% compared to full decommissioning.

show abstract

Decommissioning forecast in the deepwater Gulf of Mexico, 2013–2033

Cited by 13 publications

References 6 publications

Reaction-driven casing expansion: potential for wellbore leakage mitigation

Reaction-driven casing expansion: potential for wellbore leakage mitigation

A multi-attribute review toward effective planning of end-of-life strategies for offshore wind farms

Decommissioning vs. repowering of offshore wind farms—a techno-economic assessment

Contact Info

Product

Resources

About