CO2 geological storage prospects of Lithuania – update

The CO 2 geological storage assessment in the Cambrian saline aquifers in west Lithuania is considerably improved by 3D seismic survey of the Gargždai Elevation and Syderiai Uplift. The CO 2 storage capacity of the Syderiai site is assessed as large as 56.7 Mt (area 62 km 2 ) owing to the high reservoir properties (average porosity 17 % and permeability 400 mD) of the Middle Cambrian saline aquifer of 50 m thick and 1458-1508 m deep. The tectonic uplift is controlled by the large-scale Telšiai strike-slip fault. The Syderiai site was initially considered as the potential UGS site. The acreage of the Gargždai Elevation, comprising six depleting oil fields, is assessed 133 km 2 and the storage volume is evaluated 31.3 Mt. The main challenging parameter is a poor average porosity (7 %) and fractured type of reservoir (permeability about 10 mD) about 70 m thick and 2200 m deep. A residual oil zone (ROZ) assessment suggests are very high protentional for CO 2 combination in west Lithuania which is the only prospective site known in the Baltic region of this kind.