2. INTRODUCTION Shale gas systems are self containing petroleum systems (i.e. source, reservoir and seal all inclusive) They form continuous accumulation that is being successfully exploited commercially in the US. This is largely driven by government policy, technology and rising natural gas price. Currently, natural gas production from shale gas plays in the US stands at over 46% and it is projected to rise to 60% in the nearest future. The successful exploitation of shale gas plays in the US have sparked up exploitation in Europe, North America, etc, where shale gas plays are thought to occur.

3. showing continuous shale gas accumulation (modified after Shenk and Pollastro, 2002 )

4. N ATURAL GAS IN SHALE PLAYS The composition of shale gas is dominantly methane, with lesser percentages of propane, butane (Natural gas) According to Kennedy et al. (2012), natural gas commonly exists in shale reservoirs as: ‘free gas’ (in matrix pore network and natural fractures), ‘Sorbed gas’ (adsorbed to Organic matter and natural fractures or absorbed by the organic matter and matrix pores) and ‘Dissolved gas’ (in liquid hydrocarbons)

5. N ATURAL GAS IN SHALE PLAYS

6. C OMPOSITION OF SHALES

8. A IM AND OBJECTIVES Organic richness (TOC) of Tanezzuft gas shale Type of Kerogen present in the gas shale Thermal maturity and thermal maturity history / distribution Relative proportion of clay minerals, quartz and calcite Comparison of Tanezzuft shale properties with established shale gas plays in the USA

9. G HADAMES B ASIN B ACKGROUND ‘ Large Intracratonic - Sag basin’ (about 350,000km2) covering parts of Tunisia, Algeria and Libya. Basin fill: 8000m Conventional hydrocarbon Reserves: 32BBOE Ongoing exploration for Shale gas resources in the Tunisian end of the basin. Estimated resource 80- 120TCF (Troudi et.al, 2012) Ghadames Basin (modified after Underdown and Redfern, 2008)

11. T ANEZZUFT S HALES Deposited in the Early Silurian at the onset of widespread flooding in a Passive Margin tectonic setting World class source rock – Dominantly Type 2 kerogen – present day TOC (0.5% to > 15%) – HI values (250-450mgHc/g). 3 major lithostratigraphic units – Quartz rich upper layer – Calcite rich Intermediate layer – Basal clay rich hot shale (best source rock quality) Tanezzuft Shales Ghadames Basin Stratigraphy (after Yahi et al, 2001)

12. Data set available Data (TOC data, Maturity data, HI) from 37 wells was used for this study. Some data was obtained from Underdown (2006), Basu et al., (1997) and Yahi et al., (2001) Data set available Data (TOC data, Maturity data, HI) from 37 wells was used for this study. Some data was obtained from Underdown (2006), Basu et al., (1997) and Yahi et al., (2001) S HALE GAS EXPLORATION WORK FLOW

13. INITIAL TOC WITH 2% CUT OFF Initial TOC conversion formula (Daly and Edman, 1987) Initial TOC generally increases towards the west latitudelongitude N Initial TOC 3D Surface Map

14. Ro = 0.0180 x Tmax – 7.16 maybe unreliable where S2 values are <0.2(mg HC/g Rock) T HERMAL MATURITY (≥ 1.0% R O ) Latitude Longitude Thermal maturity generally increases towards the west (Jarvie et al., 2001) Thermal Maturity 3D Surface Map

15. S WEET S POT Wells used for Basin Modelling ONE-1 Well BRD-4 Well ‘Combining initial TOC map (2% TOC cut off) with the thermal maturity map (1% R o cut-off)’

16. B ASIN MODELLING KEY INPUT PARAMETERS Heat flow model Underdown and Redfern (2008 ) EventBegin Age (Mya) Eroded thickness (m) Alpine36.7100 Austrian120600 Hercynian2923600 Dixon et al., (2010) and Underdown (2006) Amount of exhumed overburden

17. H EAT FLOW MODEL CALIBRATION

18. BURIAL HISTORY PLOTS BRD-4 ONE-1

19. A DSORPTION POTENTIAL S CHEMATIC Pore Pressure (PSI) Adsorption Potential

20. C OMPARISON After Troudi et al., 2012

21. C OMPARISON

22. C ONCLUSION Identification of areas with sufficient organic richness (i.e. >2% initial TOC). Tanezzuft gas shale is predominantly of oil prone Type II Kerogen 1D maturity modelling reveal Tanezzuft shale to be in wet gas stage - main stage of gas generation around the ‘sweet spot’ Interbeds of quartz rich silt and fine sands exist in the Tanezzuft shale stratigraphy. Its thickness increases towards the ‘sweet spot’ The Tanezzuft shale shares a lot of similarity with the Marcellus and Utica shales

23. C ONFIDENCE / P ROBABILITY M ATRIX

24. R ECOMMENDATIONS Evaluation of the Mineralogy of the Tanezzuft Shale Investors should bare in mind the following questions: Is there adequate supply of water? What are the likely environmental issues to face? Is there adequate infrastructure? Are specialized oil field services readily available? Is there political backing for exploration?

25. ACKNOWLEDGEMENTS Thanks to God for his grace Mr James Armstrong for his wonderful supervision Other members of staff for support and encouragement Plate River Associates (BasinMod Software) TETFUND for sponsorship Thanks for Listening