Liverpool Bay Development - Oil Spill Response Strategy and its Realisation
Authors: Gilliver R.E. , Methven J.O. , Nicholls R. 
Published: December 2007

R.E. Gilliber, J.O. Methven, R. Nicholls

Robust contingency oil spill response arrangements are a prerequisite of nearshore oilfield developments. The Liverpool Bay Development (LBD) represents the greatest UK challenge to date in this regard.

This paper describes the development of BHP Petroleum E/R/AIME Region's LBD oil spill response strategy and how it was possible to implement this strategy in a very cost effective way.

The strategy was based initially on the field Environmental Impact Assessments, which had identified oil spill hazards and risks based on industry data. Additional studies and tests defined credible oil spill events, specific oil properties and coastal impacts. The types, levels and location of response requirements offshore and onshore were then evaluated - we had our strategy.

A series of in-house brain storm sessions reviewed all possible means of achieving the strategy. LBD was unique: a 4 field nearshore development with offshore crude storage and offloading. Novel solutions should be possible, resulting in a more cost effective implementation of the response strategy. Using multi-function vessels was a recurring theme - oil spill response arrangements should not be considered in isolation but together with other marine support services. A crucial step was to realise accepted practices were based on single well or single field scenarios. The company successfully opened a debate within the industry and government agencies on existing UK Regulations governing oil spill recovery, resulting in drafted, more practical Regulations and Guidelines.

A shortlist of possible vessel scenarios was then prepared. These were costed and tested against the response strategy by risk analysis, checking double jeopardy cover for all marine support services.

Government Agencies were consulted closely. This was particularly important because of the novel nature of the proposals. Their considered and positive responses enabled us to go forward with the most cost effective acceptable solution. Competitive tendering followed and achieved our expectations - robust, cost effective oil spill response arrangements.

Introduction

BHP Petroleum Ltd, formerly Hamilton Oil Company Ltd, has been operating offshore UK for over 20 years. In this time, the company has achieved a number of "firsts", notably first oil from the UK North Sea in 1975 (Argyll field), and, most recently, first oil from the Liverpool Bay Development in January 1996 marking the start-up of oil production off Britain's West Coast.

This 1.2 billion development involves oil and gas production from four fields (Hamilton, Hamilton North, Lennox and Douglas). Oil is exported via a 17km subsea pipeline to a CALRAM moored 870,000 bbl capacity oil storage installation (OSI), from which the oil is transferred to export tankers. Gas is transported via a 20" subsea pipeline to an onshore receiving and processing terminal in North Wales. It is the first integrated development in nearshore UK waters involving the production and export of both oil and gas. In total there are 7 fixed offshore installations all within 20 miles of land, with one (the Lennox platform) only 5 miles from shore.

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