Caprock properties of the Nordland Shale recovered from the 15/9-A11 well, the Sleipner area

In CO₂ underground storage operations major concern need to be directed at the integrety of the caprock. In the Sleipner Field in the Norwegian North Sea CO₂ is separated from the rich gas of the Sleipner Vest Field and disposed at 800-1100 m depth in an underground aquifer that is capped by a thick shale sequence. The shale-sand formation has not been buried to greater depths and the shale can thus be taken as an example of a shallow caprock that may well have properties very different from deeper seated caprocks known from petroleum reservoirs. Previous work have characterized the weakly consolidated caprock by indirect means; in this study reservoir condition experiments on fresh caprock samples aim at determine capillary entry/break-through pressure and in-situ poroperm properties of the Nordland Shale caprock.