AAPG DENVER THE SENEGAL BASIN EXPLORATION PRODUCTION & OPPORTUNITIES 7-10 JUNE 2009 By Ndèye Rokhaya DIALLO Basin GeologyDivision Manager

SENEGAL AREA : ~ 200 000 km2 POPULATION : ~12 000 000 DENSITY: 51 h / Km2 GNP : $ 1110 AAPG DENVER 7-10 June 09

REGIONAL SETTING The Senegal basin occupies central part of the NW African coastal basin called the MSGBC (Mauritania – Sénégal – Gambia –Guinea Bissau – Conakry). 230 000 km² (90.000 Km² offshore) AAPG DENVER 7-10 June 09

LITHOSTRATIGRAPHIC COLUMN OF SENEGAL BASIN Mesozoic-Cenozoic Passive margin Basin overling a Paleozoic basin Post-rift stage Mid Jurassic-Actual Syn-rift stage Permo Triassic- lower Jurassic Pre-rift stage Upper Proterozoic-Paleozoic AAPG DENVER 7-10 June 09

RESERVOIRS AND SEALS Upper Tertiary shaly sequences; Lower Tertiary clastics and carbonates; Upper Cetaceous sand shale sequence; Cenomanian-Turonian shales; Jurassic - lower Cretaceous carbonate section; AAPG DENVER 7-10 June 09

SOURCE ROCK AND MATURATION Best source rocks in Cenomanian-Turonian and Albian in CM-7 Cenomanian level at 2608 m with TOC = 8.72 % HI = 660 mg/g in CM-10 Turonian level at 2554 m with TOC = 5.25 % HI = 638 mg/g . AAPG DENVER 7-10 June 09

EXPLORATION HISTORY 1952 - 2008 52 500 km of 2-D seismic 76 puits 52 500 km of 2-D seismic 7 200 km² of 3-D seismic 135 exploration wells (1 well per 1.600 km²) only ~ 30 wells can be considered as significant Exploration Wells no wells in deep waters AAPG DENVER 7-10 June 09

HYDROCARBON OCCURENCIES AND PRODUCTION Diamniadio Field - 62 642 bbls Light oil 34° API, - 35 692 bbls condensate - 217 393 033 Nm3 (7.6 Bcf) natural gas. Gadiaga Field 2008 - About 72 833 389 Nm3 ( 2.54 Bcf ) natural gas - 749,12 Barrels condensate Dome Flore & Gea fields (1967) - Heavy Oil in Oligocene limestones ( 10 – 13 ° API ~ 1Bbls) - Light Oil Maestrichtian / Albian sands ( 33° API ) AAPG DENVER 7-10 June 09

GAS PIPELINE NETWORK Gadiaga field Kabor storage and epuration station Gas Turbine at Cap des Biches 34 km - 10 km - 9 km AAPG DENVER 7-10 June 09

EXPLORATION ACTIVITIES - 8 licences - 9 companies MAUREL & PROM FORTESA TULLOW ( E A ) – DANA EDISON - PETROBRAS FAR - SHELL ORANTO PETROLEUM Onshore 4 open blocs Offshore 7 open blocs AAPG DENVER 7-10 June 09

TAMNA PERMIT October 2006 90% 6 new producing wells drilled (2006-2008) Certified Reserves : 17.33 Bcf – In 2002, one producing well Gd-2 ~ 1,050,000 cubic feet/day; - In 2009, Production capacity increased to 10,500,000 cubic feet/day (new wells Sa-3, Sa-3a, Sa-4 et Sa-5 Sa-2, Sa-1B). Current phase is development of Gadiaga –Sadiaratou field Acquisition of 2000 km 2D Seismic lines to cover the onshore carbonate platform deep target. t AAPG DENVER 7-10 June 09

SEBIKHOTANE PERMIT Granted on April 2003 84.375% 15.625% 84.375% 15.625% Oil and gas have been produced from1986 to 2000 in Diam Niadio-Kabor field 1995 3-D reinterpretation defined 5 new prospects Two Prospects to be drilled in 2009 Baobab & Konkorong Target : Upper Cretaceous sands Estimated reserves : 26 & 100 BCF Main structural elements in the Area AAPG DENVER 7-10 June 09

SAINT LOUIS OFFSHORE PERMIT Granted on 2003 60% 30% 10% 1233 km 2-D lines acquired in 2006 Several interesting leads & prospects identified (Ibis, Flamingo, Fish Eagle, Vulture ) 620 km² of 3-D seismic acquired over Ibis & Flamingo prospects in 2008; 1700 km of 2-D Infill lines west of the permit and G&G evaluation planned in 2009. Play types: Shelf plays, Slope channel plays, Base slope channel plays, Counter Regional Fault Plays Shelf plays Slope channel plays AAPG DENVER 7-10 June 09

CAYAR OFFSHORE PERMIT Granted on December 03rd 2008 90 % 10 % 90 % 10 % Work Program for the first period (3 years) is mimimum 500 sq km 3-D Gainde prospect (130 km²). Post Maastrichtian channel TOP MAASTRICHTIAN DEPTH MAP Upside case Average WD : 200m Width : 2.5 - 6.5 km Length : 8 - 23 km Surface area : 19.6 - 130 km2 Vertical closure : 40 – 120 m GAINDE PROSPECT AAPG DENVER 7-10 June 2009 AAPG DENVER 7-10 June 09 14

RUFISQUE DEEP OFFSHORE PERMIT Granted August 2004 55% 40% 5% 2088 Km of 2D seismic lines; 1500 km2 of 3D data acquired on 2007; along with Gravity and Magnetic data ; Play types : Miocene slope channels play, Cretaceous turbidite wedges, and slope channels plays Estimated Reserves Total Albian OOIP from 500 to 4000 mmstb Current status ; looking for a 3rd partner before drilling a deep well A 3D cube of the 2007 survey a Oil shows at RF-3 ( 33°API ) in Senonian sands Oil and Gas shows at RF-2 and DKM-2 in Aptian/Neocomian AAPG DENVER 7-10 June 09

RUFISQUE OFFSHORE & SANGOMAR OFFSHORE granted November 2004 Farm out January 2009 (90%) 2050 km² of 3-D Seismic acquired in 2007 Play & Leads : Lower Cretaceous Carbonate shelf Margin play, Slope fan play Sea bed logging shut by EMGS in May 2009 and Financed by Santonian upper slope Stacked fans exhibiting High amplitudes 10 km Water depth meters 3D outline South channel complex Mid channel complex North channel complex Closure At top Aptian At Top Neocomain Albian Subcrop closure Lower Cretaceous Carbonate shelf Margin structural closures AAPG DENVER 7-10 June 09

1 Dome flore (Sterling Energy plc, Markmore, AGC) Managed by the AGC Two permits: 1 Dome flore (Sterling Energy plc, Markmore, AGC) - Heavy Oil in Oligocene limestones ( 10 – 13 ° API ~ 1Bbls ) - Light Oil Maastrichtian / Albian sands 2 AGC profond (Ophir Energy plc) AAPG DENVER 7-10 June 09

Saint Louis offshore Deep Cayar offshore Deep OFFSHORE OPEN BLOCKS Saint Louis offshore Deep Cayar offshore Deep 1690 km 2D on March 2006 Aeromagnetic survey - Upper Cretaceous play (Two Prospects) 1 Guelem prospect (116 km²) 2 NE Guelem prospect (114 km²) 1500 Km 2D high frequency airmag survey Two prospects: 1 Saint Louis A 2 Saint Louis B Intra Cretaceous Depth Map C.I.: 10m 10 Km Average WD : 1700m Main target : Cretaceous Width : 9.5 km Length : 15 km Surface area : 120 km2 Vertical closure : 150 m Satellite seep study economic evaluation Guelem is a 4 way dip closure 10 km wide x 13 km long AAPG DENVER 7-10 June 09

SENEGAL OFFSHORE SOUTH & SENEGAL OFFSHORE SOUTH DEEP blocks PLAY CONCEPT (1) Salt Flank Play (2) Shelf Edge Play (3) Carbonate Shelf Margin (4) Shelf Edge Onlap Wedge 1919 Neocomian Aptian Albian Jurassique Triassic - Early Jurassic Early Senonian Maastrichtian Post-Paleocene Basement 1 2 4 3 5 6 7 8 km (1) Salt Flank Play (2) Shelf Edge Play (3) Carbonate Shelf Margin (4) Shelf Edge Onlap Wedge (1) (2) W E (4) 10 -Paleocene Campanian (3) Cenomanian Turonian Depth AAPG DENVER 7-10 June 09

ONSHORE BLOCKS, THE PALEOZOIC BASIN Underly the Meso Cenozoic passive margin Basin Acreage : ~ 60 000 km² LOUGA DIOURBEL SALOUM SENEGAL ONSHORE SUD AAPG DENVER 7-10 June 09

Two tectonic styles compressional regime in the rest of the Senegal basin resulting from the combined effect of Caledonian and Hercynian orogenies Extensional system in Eastern Casamance in which a pre-hercynian structural style of Horsts and Grabens and tilted fault blocks was preserved AAPG DENVER 7-10 June 09

RESERVOIRS AND SEALS Possible Permo-Carboniferous sediments Upper Devonian shales Lower Devonian sandstones, (porosities 15- 20 %) Silurian shales Interbedded shales Ordovician sandstones with secondary porosity and permeability due to fracturing AAPG DENVER 7-10 June 09

SOURCE ROCK AND MATURATION Silurian shales : best regional source rocks TOC ~ 1% - 3% Ro ~ 0.95 - 1.3 Oil windows should occur between 1850/2400 m to 3400/4000 m AAPG DENVER 7-10 June 09

TRAPS AND PLAYS - 5630 km 2D in Louga, Diourbel, Saloum - 2770 km 2D in Senegal Onshore Sud ; 15 anomalies distributed at depth ranging from 2,600 to 5,700 m of Ordovician to Carboniferous age. Trapping : trusted anticlines, complex faulted anticlines, four way closures, tilted fault blocks. Seismic Line DL 71-01-07 AAPG DENVER 7-10 June 09

SALOUM & SENEGAL ONSHORE SUD PERMITS ONSHORE OPEN BLOCKS 1 - LOUGA Acreage : 27000 km2 7 wells (1 well per 3857 km2 ) 2 - DIOURBEL Acreage : 17 265 km2 3 wells (1 well per 5 755 km2) 3- THIES and MBOUR THIES: 2067.8 km2 MBOUR : 1380 km2 Paleozoic " A prospect " SALOUM & SENEGAL ONSHORE SUD PERMITS Granted on December 03th, 2008 Saloum Work Commitment: Minimum 750 km of 2D Seismic line Minimum 660 km² of 3D Seismic 2 exploration wells Senegal Onshore Sud Work Commitment: Minimum 450 km of 2D Seismic line Minimum 400 km² of 3D Seismic 2 exploration wells AAPG DENVER 7-10 June 09

PETROLEUM LEGISLATION LEGAL AND FISCAL TERMS AAPG DENVER 7-10 June 09

LAW N° 98-05 of January 08, 1998 (PETROLEUM CODE) PRODUCTION SHARING CONTRACT (PSC) EXPLORATION Initial Period: 3-4 years Renewal Periods: 2-3 years EXPLOITATION PERIOD Initial Period: 25 years Extension Periods: 10+10 years AAPG DENVER 7-10 June 09

EXPLORATION WORK PROGRAM & EXPENDITURE OBLIGATIONS to be negotiated RETENTION PERIOD If a discovery is certified non commercial, Contractor may be granted a Retention Period of maximum: 3 years for crude oil 8 years for natural gas AAPG DENVER 7-10 June 09

PETROSEN’S PARTICIPATION Exploration phases: Carried Interest of up to 10 % After Commercial discovery: Working Interest up to 20 % FISCAL REGIME Twenty five per cent (25%) Income Tax ( applied on net profit ) AAPG DENVER 7-10 June 09

MAIN CONCLUSIONS Senegal Basin has generated oil and gas: Diamniadio, Gadiaga and Casamance Dôme Flore fields; Presence of world class source rocks in Turonian-Cenomanian, secondary good sources in Albo-Aptian and Jurassic; Petroleum system in Deep water with various structural trends and traps; 60 000 km2 of underexplored Paleozoic basin with good reservoirs in Ordovician and Devonian, and good source in Silurian, traps and plays identified. Law with flexible terms AAPG DENVER 7-10 June 09

THANK YOU AAPG DENVER 7-10 June 09