Cygnus Field Late Life Seismic Rejuvenation & Quantitative Reservoir Characterisation

The Cygnus field is currently the largest producing gas asset in the UK southern gas basin and has been on production since 2016. Legacy seismic data quality has, to date, limited attempts to utilise quantitative seismic reservoir characterisation workflows. The over reliance on full stack amplitude behaviours to infer views on reservoir and hydrocarbon presence has over time been shown to be highly non-unique in nature. A recent ground up, objective driven, re-processing of the underlying seismic data at Cygnus has now delivered AVO compliant pre-stack data that has allowed the asset to exploit elastic domain rock physics responses observed on reservoir log data via the utilisation of a novel pre-stack probabilistic one-step inversion for seismic facies. The impact of this recent work at Cygnus has been transformational leading to revised views on both reservoir presence and architecture for both Carboniferous and Permian producing intervals. As the field transitions into a new phase of its development life, this rejuvenation of the seismic data will have a material impact on future investment opportunities enabling the Cygnus joint venture to maximise the economic recovery of one of the UK Southern gas basins most strategic assets.