Geology and organic petrography of the Nagoorin oil shale deposit

Abstract

An in-situ shale oil resource of 2.65 × 10 9 barrels has been delineated by exploratory drilling in the northern part of the Nagoorin Graben known as the Nagoorin deposit. The drilling has defined a mid to late Eocene sedimentary sequence in excess of 870 m thick. The Tertiary rocks have been divided into five conformable sedimentary units (B to F) and, with the exception of the basal unit B, all contain significant beds of oil shale. Eighty samples from the deposit, examined using fluorescence microscopy for the included organic matter, with specific reference to the nature of the liptinite macerals, are shown to belong to one of three groups: 1. cannel coals and canneloid carbonaceous shales-generally dull, black in colour but containing bright vitrinite bands up to 2 mm thick; 2. lamosites and carbonaceous lamositesbrown to dark greyish-brown oil shales containing dominantly lamalginite but also minor vitrinite; and 3. claystones and carbonate-rich claystones containing trace amounts of alginite, vitrinite and resinite.