PERMANENT CARBON SEQUESTRATION POTENTIAL IN OFFSHORE BASALT SEQUENCES ON THE NW EUROPEAN CONTINENTAL MARGINS

A dramatic reduction in global greenhouse gas emissions is necessary to achieve climate change targets. Wide ranging measures are required to reduce emissions with carbon capture and storage forming a vital component. Current carbon sequestration occurs in volumes of Mt/a into dominantly sedimentary reservoir rocks. Pilot tests have demonstrated that basalt reservoirs provide an alternative and permanent carbon capture scenario (e.g. Carbfix project). Here, we use 2D and 3D seismic data combined with well data to identify and map potential permanent and safe carbon storage reservoirs in offshore basalt sequences in the NE Atlantic. Well data support the presence of reservoir properties within extrusive basaltic sequences with porous lava flow tops and volcaniclastic lithologies comprising the most prolific sequestration targets. The basalt sequences are overlaid by several hundred meters of Cenozoic sediments with sealing properties, consisting mainly of marine shales and glaciogenic sediments. We hypothesize that offshore CO2 sequestration into porous basaltic lava flows may allow permanent CO2 sequestration of several gigatons per year, however more research and testing is needed to verify this potential.