Jonathan Charles Side

The future of North Sea oil industry abandonment in the light of the Brent Spar decision

In June 1995 Shell UK announced its intention not to dispose of the Brent Spar in accordance with the declared Best Practicable Environmental Option, that of disposal in the deep sea, suggesting first that this would mean a land-based disposal option would be sought, but later its intention to invite and consider any option that was put forward. This decision which followed one of the most public environmental protests in Europe has thrown North Sea abandonment into the public spotlight, and leaves the existing legal and policy approaches to the abandonment of the northern North Sea oil fields in a state of confusion. This paper seeks to investigate the circumstances which led to this about-turn and to elaborate the possible consequences of this in terms of the policy approaches and specific procedures previously adopted to satisfy the requirements of international law. More specifically it seeks to identify the circumstances which might allow for a successful future partial abandonment option (i.e. one that involves the disposal of part or parts of an installation at sea), and attempts some conclusions regarding the influence of science and broader societal values on such decisions.

Rigs to Reefs in the North Sea

In the next two decades, the UK will have to decommission most of its offshore platforms, when they cease cost-effective production and become redundant. This has resulted in considerable discussion over the past 10 years about the engineering, legal, financial and environmental aspects of decommissioning (Read, 1984, 1985; Side, 1993; Side et al, 1993). A framework of regulations and standards for North Sea platform decommissioning is in place including guidelines drawn up by the International Maritime Organisation in 1989. In the wake of the Brent Spar incident, however, there has been considerable debate on the disposal at sea of offshore installations. This has resulted in the contracting parties to the 1992 OSPAR Convention for the Protection of the Marine Environment of the North- East Atlantic agreeing a Decision (98/3) on the Disposal of Disused Offshore Installations, to enter into force in February 1999. This decision prohibits the leaving wholly, or partly in place, of disused offshore installations within the maritime area, the only potential exceptions being the footings of steel installations weighing more than 10 000 tonnes in air; gravity based and floating concrete installations; concrete anchor bases; and any other installation suffering exceptional or unforeseen circumstances resulting from structural damage, deterioration or equivalent difficulties. This decision, however, does not cover those installations which serve another legitimate purpose in the maritime area authorized or regulated by the competent authority of the relevant contracting party. These installations are subject to Annex III (Article 8) of the 1992 OSPAR Convention and other relevant UK and international legislation and guidelines, the former requiring authorization from the contracting party in accordance with relevant applicable criteria, guidelines and procedures adopted by the Commission, with a view to preventing and eliminating pollution.

Correcting for mesh size dependency in a regional model's representation of tidal turbines

When regional-scale hydrodynamic models use fine mesh sizes, such that the cross-section of a cell approaches that of a turbine, an error emerges in the calculation of turbine thrust. This error can be corrected using a method derived from actuator disk theory. We demonstrate this error, explain its source, and then present and test a new MATLAB package to correct for it. Although some minor mesh dependency remains after the correction, its effect is reduced by an order of magnitude. Keywords—numerical modelling, marine renewable energy, tidal energy, energy extraction, MIKE 3

Baselines and Monitoring Methods for Detecting Impacts of Hydrodynamic Energy Extraction on Intertidal Communities of Rocky Shores

As part of the UK government’s objective to deliver an increasing proportion of electricity from renewable sources, West Mainland, Orkney, is at the forefront of the development of wave-energy extraction devices. Exposure to wave energy plays a dominant role in shaping the Orkney landscape and determining the ecological community, but little is known of the consequences of commercial scale removal of energy from the environment. An extensive long-term monitoring programme to assess the impacts of altering wave-energy exposure on these rocky shores alongside responses to other systemic forcing agents such as climate change is continuing. Within the programme are photographic surveys, including quadrat and fixed viewpoint techniques, littoral studies of sentinel species, and the development of cost-effective wave-energy quantifying devices. Software has been developed to analyse images efficiently, to produce quantitative data on species and biotope coverage. Additionally, extensive surveys along the shoreline provide detailed image records, including areas without prior scientific description, and have helped identify locations of environmental sensitivity. Collectively, the data provide a comprehensive pre-development baseline along this important coast.

THE QUANTIFICATION OF ENERGY CONSUMPTION AND GASEOUS EMISSIONS ASSOCIATED WITH DECOMMISSIONING OFFSHORE OIL AND GAS INSTALLATIONS

Abstract Following the failure to implement the proposed deep-sea disposal of the North Sea Brent Spar oil installation the UK oil industry has identified energy consumption and gaseous emission as a key determinant of environmental impact associated with the abandonment of offshore facilities. In the absence of a standardised methodology this paper describes the approach adopted and results achieved using the North Sea Heather platform as a case study. The study develops and then applies a set of rules for conducting such analyses. Results show that in terms of energy consumption and greenhouse gas emissions there is little to choose between most partial and complete removal options. The energy cost advantages of recycling are largely offset by increased transport costs returning materials to shore. The study also highlights the importance of case specific variables, in particular, marine vessel fuel consumption.