Lake Tanganyika Blocks

Tanganyika Graben Blocks

Eleven blocks will be included in the licensing round:

Uvira

    • Area = 1600 km2

Baraka

    • Area = 1600 km2

Kibanga Kisoshi (Block 03)

    • Area = 1694 km2

    • Exploration Theme:

      • Miocene | Karroo

Kakelwa-Babobo

    • Area = 1400 km2

Kabimba

    • Area = 1800 km2

Kalemie (Block 06)

    • Area = 2600 km2

    • Exploration Theme:

      • Miocene | Karroo

Kibi-Fatuma

    • Area = 1600 km2

Mpala

    • Area = 2550 km2

Moba

    • Area = 2100 km2

Kituku Moliro (Block 10)

    • Area = 2600 km2

    • Exploration Theme:

      • Miocene | Karroo

Mulula Lugamba (Block 11)

    • Area = 4631 km2

    • Exploration Theme:

      • Permian-Carboniferous

Resource Potential

Petroleum Resources Estimated:

  • 3.346 - 5.694 billion barrels

    • Source: IOC

  • 10 billion barrels

    • Source: SONAHYDROC / FRACGEO

Previous Studies

Tanganyika Blocks Previous Studies

Location

The Tanganyika Graben is part of the grabens of the West Branch of the East African Rift. It is shared between Burundi, the Democratic Republic of Congo, Tanzania and Zambia.

As a whole, the Tanganyika Graben as a sedimentary basin, covers an area of ​​approximately 35,000 km² including 32,500 km² offshore and 2,500 km² onshore (the Ruzizi plain in the North). The area of ​​the Congolese part of Tanganyika Graben is approximately 16,500 km² (~15,500 km² offshore and ~1,000 km² onshore).

Lake Tanganyika, 650 km long, 50 to 80 km wide and having a depth of about 1470 km, is the second African lake by its surface after Lake Victoria. It is fed by two main rivers, the Ruzizi and the Malagarasi. Its waters join the Congo Basin, via the Lukuga River, then the Atlantic Ocean.

Geological and Structural Context

The Lake Tanganyika sedimentary basin has a syn-rift series of at least 6,000 m thickness comprising three sedimentary sequences:

  • A Miocene fill consisting of lacustrine clays, turbiditic sands and conglomeratic fans whose thickness is ±5,000m;

  • Fluvio-lacustrine sand and silt formations from 500 to 2,000m

  • Deltaic sediments with coal and lacustrine clays (300-2000m) from the Permian;

The Karoo formations observable on the surface in the Luama Trough would dip into Lake Tanganyika in the centre.

2D multi-track reflection seismic data show that the geomorphology of the Tanganyika Graben is characterized by a mosaic of 7 asymmetrical sub-basins, rectangular in piano key shape, oriented NNE-SSW to NW-SE.

Structurally, these sub-basins are depocenters grouped into 2 distinct main sections separated by the Kalemie Shoal (Figure 47), (Tiercelin and Mondeguer, 1991):

  • North Section consisting of the Bujumbura, Rumonge, Kigoma and Ruzizi Sub-Basins which in turn is separated from the North Section by the Ubwari Shoal;

  • Southern Section consisting of the Kalemie, East-Marungu and Moba Sub-Basins.

Stratigraphic column of the Tanganyika Graben Basin
Structure of the Tanganyika Graben Basin
Map of the sub-basins of the Tanganyika Graben Basin
South Depositional Basin – Seismic line 214 Geo-seismic interpretation (modified after Duke University/Amoco work)

Hydrocarbon Potential

To date, the oil interest in the Tanganyika Graben is thanks to the various exploration works carried out both in this sedimentary basin and in the region of the West Branch of the East African Rift. We notice :

  • About 2,100 km of 2D seismic reflection acquired in Tanganyika Graben in 1980 by the PROBE Project (DUKE University, USA);

  • 2 wells drilled onshore in the North of Tanganyika Graben (AMOCO, 1987): Buringa-1 well and Ruzizi-1 well;

  • 2 wells drilled southeast of Tanganyika Graben in Lake Rukwa (AMOCO, 1987): Ivuna-1 well and Galula-1 well;

  • Several oil seeps documented including the spectacular underwater seeps of Cape Kalamba;

  • Important discoveries in the Ugandan part of the Albertine Graben where the Late to Middle Miocene Kisegi Sandstones are considered as the main theme of Exploration.

  • The presence of hydrothermal vents is an adequate indication for the maturation of organic matter;

  • Several prospects or hydrocarbon areas highlighted:

    • Prospects associated with tilting of stage 2 fault blocks;

    • Stage 2 turbiditic sedimentation prospects;

    • Stratigraphic and structural prospects.

Petroleum Systems of Lake Tanganyika Basin

Source rocks

Lacustrine argillites of the Miocene:

  • TOC: 2 to 5%;

  • Type I Oil-Prone, mature

Formation of LUKUGA (Permo-Trias):

  • T.O.C: ≥3.8%

  • Type III Gas-Prone, mature

Layer of Charcoal argilites (Permian sediments):

  • T.O.C: 1.69 at 3%

  • Type I Oil-Prone, mature

Permian lacustrine argillites:

  • TOC: 2 to 4%

  • Type I Oil-Prone, mature.

Reservoir Rocks

  • Tertiary turbiditic sands;

  • Fluvio-continental sands of the Permo-Trias;

  • Permian deltaic sands;

  • Permian basic conglomeratic sandstones with a porosity >31%

Cap Rocks

  • Palustrine sediments and thick clays,

  • Organic muds with compacted diatoms,

  • Clay-silty deposits;

Traps

  • Tilted blocks and facies changes (stratigraphic and structural traps).