Dutch North Sea Logger Field – Experts to Court of Appeal in the Hague

The Logger Field is a small Dutch offshore oilfield operated by Conoco. In 1992 Unocal (subsequently Chevron) claimed that the field extended to their adjacent acreage and requested a pooling arrangement. Legal proceedings commenced following denial of this claim by the authorities and ultimately, following several reversals, a civil claim for damages was upheld. A 2003 decision by the Court of Appeal (The Court) ruled that Conoco had unwittingly produced some of Unocal’s oil and should pay compensation.

Due to the technically complex nature of this dispute, RPS were appointed the 'Named Experts' by The Court to provide relevant advice in relation to Unocal's claim.


The Court formulated specific questions for RPS in relation to Unocal’s claim. The questions probed issues such as the amount of oil that had migrated across the license boundary as a result of Conoco’s activities, and whether the remaining oil in Unocal’s block was consequently less productive as a result. Since the field was never unitized, Ian Linnett advised The Court as to what Unocal might have produced without the influence of prior production in the adjacent block, and what profits might have resulted.

A range of potential scenarios were forward modelled from time-zero based on a comprehensive, integrated static and dynamic model, having first established a valid history match to actual production. This required detailed technical, procedural and commercial analysis to deliver a result The Court could rely on after more than a decade of legal and commercial dispute.


The RPS team has deep expertise in this area, frequently acting as Expert in hydrocarbon ownership disputes in field redeterminations. Their approach was to initially establish a process and protocol where both the parties provide data and submissions to us to review. Subsequently each part has an opportunity to comment on our 'Initial Decision' prior to issue of the 'Final Decision'.

We created a history-matched 3D reservoir simulation which we then ran forward modelling of multiple 'imagined' scenarios. These involved economic evaluation to establish Net Present Value (NPV) for a series of cases, and incorporating economic evaluation including the establishment of cost estimates for different production cases. Our challenge was to produce a pragmatic solution that would withstand scrutiny and be accepted by deeply divided parties.

The Expert’s Final Report was accepted by The Court to fix the matter of damages. And following a series of further hearings the parties ultimately settled the matter out of Court for an undisclosed and confidential sum.

Further details are publicly available as a matter of public record in Court Papers.

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