1. PETROLEUM POTENTIAL OF THE ALBERTINE GRABEN, UGANDA, CONFIRMED
Presented By
Reuben Kashambuzi
Commissioner,
Petroleum Exploration and Production Department, Uganda
at the AAPG Convention 2006, Houston, Texas, USA

2. PRESENTATION OUTLINE Regional Setting of the Albertine Graben
EARS
Volcanism
Structural Setting
Hydrocarbon Play Indicators
Source rocks
Reservoirs
Traps
Seals
Concluding Remarks
Key facts about Uganda
Investment Opportunities

3. REGIONAL SETTING The EARS bifurcates into two arms
Eastern and Western arms separated by Tanzanian Craton
Northern most part of the Western arm of the East African Rift System
500 Km long, averaging 45 km wide and 23,000 sq km
Volcanic processes are not widespread in the Western arm as they are in the Eastern arm
Ethiopian rift
Albertine
Graben
Aswa Shear Zone
Tanzanian
Craton
EARS

4. Summary tectonic map of the Albertine Graben
STRUCTURAL SETTING
Grabens and half grabens separated by accomodation zones
Graben strongly shaped by;
Continental Extension – NW-SE
Strike slip
Three structural domains:
Northern trends in a NNE-SSW
Central trends in a NE-SW
Southern trends in a NNE-SSW
Central Domain: Orthogonal extension
Northern & Southern Domains: Oblique Extension
Summary tectonic map of the Albertine Graben

5. HYDROCARBON PLAY INDICATORS
Source Rocks:
Rocks with good source potential have been mapped in the Graben e.g. Kaiso Tonya.
Good source rocks reported in the Waki-B1, Turaco, Mputa and Waraga wells
Inferred from oil seeps
High quality lacustrine mature source rocks encountered in the wells drilled on the Turaco, Mputa and Waraga prospects.
Kaiso-Tonya shale

6. HYDROCARBON PLAY INDICATORS Cont’d☼ ☼
Turaco-2 Lithology log. Good source rocks were reported in the well
Waki B-1 Lithology log. Excellent source rocks were encountered

7. HYDROCARBON PLAY INDICATORS Cont’d
Reported Oil Seeps
Oil Seepages
Distributed along the entire length of the Albertine Graben
Different geochemical characteristics indicating multiple sourcing
Radar Imagery of the Albertine Graben showing interpreted and confirmed oil seeps

8. HYDROCARBON PLAY INDICATORS Cont’d
Oil Seepages
Oil Seepage in highly crushed basement at the Kabyosi oil seep in Kaiso – Tonya area
Oil film floating on the Victoria Nile
Oil seep from shallow well at Kibiro 23
Oil impregnated channel sandstone of the Kaiso FM on the banks of R. Hohwa

9. HYDROCARBON PLAY INDICATORS Cont’d
Reservoir rocks:
Thick ( m) and well sorted sandstones
Good porosities of the order of 30%
Good permeability
Multiple pay zones confirmed by drilling (Mputa-1 and Waraga-1)
Sebugoro Formation
Hohwa oil sandstone
Kisegi Formation

10. HYDROCARBON PLAY INDICATORS Cont’d
Traps:
Sedimentary structures in the Graben are basement related
Residual gravity anomalies reveal several structures
Structures have been confirmed by seismic data and tested by exploration drilling
Compares well with Sudan where major oil fields coincide with gravity highs
Residual gravity anomaly map of EA2, showing distribution of gravity highs oil seepages and well locations

11. HYDROCARBON PLAY INDICATORS Cont’d
Semliki structures
Turaco-1,2&3 drilled on a gravity high
Turaco – Encountered natural gas contaminated with CO2 in the ratio CH4 : CO2 of 1:4
Good reservoirs
High flow rates (60 mmcft/d)
Good seals
Good source rock quality
Multiple reservoirs
Shallow biogenic (?) gas ( m depth)
CO2 not extensive
Gravity reveals other significant subsurface structures also confirmed by seismic
Saddlebill
Residual gravity anomaly map of Semliki Basin, EA3A

12. HYDROCARBON PLAY INDICATORS Cont’d
Kaiso-Tonya structures
Mputa and Waraga Prospects tested by exploration drilling
Rich shales
Oil shows
Oil samples extracted for lab. analyses
Multiple reservoirs
Thin sandstones
Shows in fractured basement
Wells cased and suspended for re-entry for testing
Mputa #1
Waraga #1
General geology of Kaiso-Tonya showing the Mputa and Waraga well location

13. HYDROCARBON PLAY INDICATORS Cont’d
Kaiso-Tonya structures
Mputa and Waraga Prospects coincide with significant gravity highs
The gravity structures have been confirmed by seismic data
Prospectivity of other structures still to be confirmed
Residual gravity anomaly map of Kaiso-Tonya, EA2

14. HYDROCARBON PLAY INDICATORS Cont’d
Typical traps
Flower Structures
Rollover anticlines
Inversion anticlines
Potential for stratigraphic traps
Seismic section showing an inversion anticline in Semliki Basin

15. HYDROCARBON PLAY INDICATORS Cont’d
Traps Cont’:
Syncline
Inversion
Anticline
5 Km
Structural highs observed on the seismic sections are potential hydrocarbon traps - inversion anticlines
Structural lows represent possible ‘Kitchens’

16. HYDROCARBON PLAY INDICATORS Cont’d
Seals:
Alternating shales and sandstones observed in Waki-B1 well suggest good sealing mechanism
Wide spread clays, some quite thick, provide regional seals. Clays have been mapped across the Albertine Graben
Observations from Turaco, Mputa and Waraga exploration wells confirm effective seals
Waki B-1 well lithology. Oil shows were encountered at 3850 ft

17. KEY FACTS ABOUT UGANDA Population Size: 27 million people
Size of country: 241,038 Sq. Km
GDP: US$ 6.8 Billion
Export Earnings: US$ Million (2004)
Fuel Consumption: 681,248.8 m3 (US$ m/year), 2005
Installed Capacity: 300 MW of electricity
Available Power: MW of electricity
Power demand: ~ 500 MW of electricity
Power shortage: Effect of prolonged drought
Thermal Generation: 50 MW to increase to 200 MW (End 2006)
Confirmation of shallow gas in Turaco would alleviate the problem

18. INVESTMENT OPPORTUNITIES
AVAILABLE ACREAGE
EA5 Rhino Camp Basin
Size: 6,040 Sq. Km
Licensed: Neptune Petroleum (U) Ltd on 27th Sept 2005
EA1 Packwach Basin
Size: 4,285 Sq. Km
Licensed: Heritage Oil and Gas (U) Ltd on 1st July 2004
EA2 Lake Albert Basin
Size: 4,675 Sq. Km
Licensed: Hardman Resources (U) Ltd on 8st October 2001
EA4 Lakes Edward-George Basin
Size: 5,910 Sq. Km
Not yet licensed
EA3A Semliki Basin
Size: 1,982 Sq. Km
Licensed: Hearitage Oil and Gas and Energy Africa on 8th Sept 2004
EA3B Semliki Basin
Size: 1,795 Sq. Km
Not licensed
Exploration Area 3
Exploration Area 4
5,910 Sq. Km
Acreage on land and on the lake
Geological & Geophysical data
Sediment thickness, over 4 Km
Exploration Area 3B
1,795 Sq. Km
390 Sq. Km of 3D seismic data
410 Line Km of 2D seismic data
Lithology and wire line data from 3 wells
Structures with potential for ;
Gas condensate
Shallow biogenic gas
High quality reservoir conditions established

19. PLEASE CONTACT
Uganda Booth No at the International Pavilion OR. The Commissioner, Petroleum Exploration and Production Department, 21–29 Johnston Road P. O. Box 9, Entebbe (Uganda) Tel: Website:

20. THANK YOU