1. CO 2 storage capacity estimates for South Africa: The uncertainties and way forward J.H.A. Viljoen, M. Cloete, F.D.J. Stapelberg and N. Hicks

3. Scale of assessment Availability of data Quality of data Assumptions that have to be made in the calculation of capacity estimates Storage Efficiency Factor Injectivity and Containment Non-geological factors Uncertainties

4. Scale of assessment (CO2CRC, 2008)

5. Availability and quality of data Public domain Published articles/books Petroleum Agency SA (off-shore) Council for Geoscience (onshore)

6. (CO2CRC 2008)

8. Data Confidence Indicator (after US DOE, 2007)

10. Scale of assessment Availability of data Quality of data Assumptions that have to be made in the calculation of capacity estimates Storage Efficiency Factor Injectivity and Containment Non-geological factors Uncertainties

11. Assumptions that have to be made to calculate storage capacities CO 2 STORAGE CAPACITY ESTIMATION FORMULAE Deep saline reservoir:M CO2 = A h g φ tot ρ E Symbols: M CO2 = Mass estimate of CO 2 storability A= Geographical area of formation h g = Gross thickness of formation φ tot = Average porosity of formation ρ = CO 2 density at storage pressure and temperature E= Storage efficiency factor

12. BoreholeSequence Depth to potential reservoirs (m) Nett Sandstone (m) Porosity (%) Permeability D-A1 9At1 – 13At11 051 – 1 2253919 – 26Good 6A1 596 – 1 717308 - 13Poor - Fair 1At1 – 5At12 202 – 2 2321910Ave. 10 mD D-B1 5A1 170 – 1 2422425Good 5A1 486 – 1 5352820 – 24Fair – Good 1At1 – 5At11 805 – 1 8301712 – 19Fair 1At1 – 5At11 864 – 1 8932923Good D-C1 DCII – 1At11 782 – 1 806216 – 9Poor DCII – 1At11 818 – 1 8281023Fair D-D1 13A1 503 – 1 5473525Good 9At1 – 13At11 606 – 1 6702420 – 25Good E-B1 13A1 075 – 1 1202725 – 26Good 6A1 164 – 1 2708225 – 26Good 5A1 347 – 1 3762923 - 24Good Average~ 80~ 20

13. Storage Efficiency factor (that part of the total pore volume that can practically be filled by CO2) Atlas: 10% Currently: 1 – 4% Even < 1%

14. Containment and Injectivity Size of Reservoir/Porosity (Volume) Cap rock, trap, faults (Containment) Permeability/Pressure regime (Injectivity)

15. Non-geological factors Source/sink matching Transport Detail Land-use

16. Way forward ( parallel to the CCS Roadmap of the SACCCS ) Assessment and evaluation of all potential basins and sub-basins as identified in the Atlas (existing unpublished data – Petroleum Agency SA) Sub-basins must be assessed and rank Identify gaps in the existing data Pre-competitive Prospecting (acquire new and additional) data if needed Effective/practical storage capacity assessment of suitable basins/sub-basins if possible Promotion and licensing Areas with low hydrocarbon prospects (source rocks) but with good reservoirs and cap rocks; hydrocarbon depleted areas Prospecting and verification (site selection) This process must start as soon as possible

18. Carbon Capture and Storage Acreage Release The Offshore Petroleum and Greenhouse Gas Storage Act 2006, which came into force on 21 November 2008, provides for a system of access and property rights for the geological storage of greenhouse gas in offshore waters under Commonwealth jurisdiction. As the first step in the process of providing these access and property rights, the Minister for Resources and Energy release ten offshore areas for the exploration of greenhouse gas storage areas. These release areas are located in the following basins:Offshore Petroleum and Greenhouse Gas Storage Act 2006 Gippsland Basin Torquay Sub-basin Otway Basin Vlaming Sub-basin Petrel Sub-basin The document, Guidance Notes for Applicants sets out information for prospective applicantsGuidance Notes for Applicants Please note the varied closing dates for applications for GHG assessment permits: Friday 30 September 2011 for release areas GIPP-01, GIPP-02 and GIPP-03; and Friday 30 March 2012 for the remainder of the release areas (TORQ-01, TORQ-02, OTWY-01, VLAM-01, VLAM-02, PTRL-01 and PTRL-02) In all other respects the original conditions for application and assessment accompanying the April 2009 Gazettal remain the same. Well data and geophysical data are provided for release areas.

19. Summary It should be understand that the Atlas is a Country Scale Assessment of South Africa's geological storage potential of CO 2. There are still uncertainties/gaps in the storage potential/capacity estimates of South Africa’s basins. Basins identified as potential CO 2 storage sites should be investigated further up to a point that private investors have a better understanding of the risks involved so that they can make investment decisions. If the S.A. Government is seriously about CCS, resources should be made available to achieve this.

20. Thank you