External review of the storage plan for the Peterhead Carbon Capture and Storage Project

摘要

This document summarises the findings of an external independent review of the storage plan forudthe proposed Peterhead Carbon Capture and Storage project which aims to store up to 20 millionudtonnes (Mt) of CO2 within the framework of the European Directive on the geological storage ofudCO2.udThe Peterhead Carbon Capture and Storage Project proposes to capture carbon dioxide (CO2)udfrom an existing gas-fired power-station at Peterhead and to store this in geological strata at auddepth of around 2600 m beneath the outer Moray Firth. The plan is to store 10 - 15 Mt of CO2udover a ten to fifteen-year period commencing around 2020, but the site is being qualified for 20udMt to allow for potential extension of the injection period. Storage will utilise the depletedudGoldeneye gas condensate field with the Captain Sandstone reservoir as the primary storageudcontainer. The Storage Site covers some 70 km2, and comprises the Captain Sandstone andudunderlying strata of the Cromer Knoll Group, bounded by a polygon some 2 to 3 km outside ofudthe original Goldeneye oil-water contact. The Storage Complex is larger, around 154 km2,udbounded some 2 to 7 km outside of the original oil-water contact, and extending upwards to theudtop of the Dornoch Mudstone at a depth of more than 800 m. The top-seal of the primaryudcontainer is a proven caprock for natural gas and is formed by the mudstones of the UpperudCromer Knoll Group, the overlying Rødby and Hidra formations and the Plenus Marl. A numberudof additional seals are present in the overburden within the Storage Complex, as are a number ofudpotential secondary containers which could also serve as monitoring horizons.udThe geological interpretation of the storage site is based on the comprehensive datasets acquiredudduring the discovery, appraisal and development of the Goldeneye field, and also data from otherudwells, fields and seismic surveys in the surrounding area. The static geological model of theudstorage site and adjacent aquifer has been stress tested for the key uncertainties, and it isudconsidered to be robust. The storage capacity of the Goldeneye structure has been calculatedudusing both static (volumetric) methods and dynamic flow modelling together with uncertaintyudanalysis. Total estimated capacity of the structural closure is in the range 25 to 47 Mt and soudrobustly exceeds the proposed injected amount.