Albertine Graben Blocks

Albertine Graben Blocks

Four blocks will be included in the licensing round:

Bloc I

    • Area = 3880 km2

Bloc II

    • Area = 3090 km2

Bloc IV

    • Area = 4481 km2

Bloc V

    • Area = 6581 km2

Resource Potential

Petroleum Resources Estimated:

  • 5.463 billion barrels

    • Source: IOC

Location

The Albertine Graben, with an area of approximately 22,000 km2 in the Congolese part of the Basin (~14,000 km2 for the Lake Albert Basin and ~8,000 km2 for the Lake Edward Basin), is part of the West Branch Basins of the East African Rift and is located between 1°26' and 2°30' South latitude and between 29°00' and 31°31' East longitude, east of the Democratic Republic of Congo.

Geological & Structural Context

In the Albertine Graben, sediment fill was from the Mesozoic (Jurassic or Cretaceous) to the Quaternary. The formations, probably of continental origin, consist of sands, sandstones, conglomeratic sandstones, bituminous shales with alternating sandstone formations, indurated clays, green clays, breccias, conglomerates and lignites, all resting on the crystalline base.

The thickness of the sediments is ~6000m.

The Lake Albert-Semliki Trough is a graben aligned with a major lineament marked by several structural features, particularly carbonatite and kimberlite intrusions. The alkaline intrusions are dated to the Lower Cretaceous, suggesting the initial phase of Lower Cretaceous rifting.

South of the Lake Albert-Semliki Graben is the Lake Edward Graben. The two grabens are asymmetrical and separated by a large Precambrian basement block, Mount Ruwenzori, which culminates at 5,100 meters above sea level. The latter creates favourable conditions for setting up structural and stratigraphic traps, thus constituting exploration objectives.

Overview of the basins of the West Branch of the East African Rift
W-E section of Lake Albert and location of the BUTIABA WAKI-1 borehole (Uganda Ministry of Energy, 2004)

Petroleum Potential of the Albertine Graben

The oil potential of the Albertine Graben is clear.

The various discoveries made in the Ugandan part of the Basin sufficiently prove that the oil system has worked well in the Albertine Graben Basin.

In addition to the discoveries mentioned above, several favorable factors for oil exploration and production have been identified in this Basin. These include oil seeps and gas fumes reported along the border faults respectively at Kibiro, Kibuku, Butiaba, Kasenyi and Waki ​​on the Ugandan side of this Graben and at the localities Ziga, Songa Mbili, Gobu Jii , Muganga and Nzonzo on the Congolese side of the Basin. (Experts from the General Secretariat for Hydrocarbons in 2007 and 2008).

Based on the various discoveries made on the Ugandan side of the Albertine Graben, the probability of success in Blocks I, II, III, IV and V is high (70%). The volume of oil in place (OOIP) that can be exploited without risk is estimated at approximately ~5463 MMbbl divided into 23 onshore prospects and 5 offshore prospects.

Oil shows in Butiaba and Waki (Uganda)
Surface oil shows in the Congolese part of the Albertine Graben (along Lake Albert, Blocks I and II)

Petroleum Systems of the Albertine Graben

The various exploration works carried out on both the Ugandan and Congolese sides further prove that the oil system has worked very well in the Albertine Graben.

Reservoir Rocks and Cap Rocks

  • Middle and Upper Miocene sandstone (Kisegi sandstone)

  • The fault formation of Garamba covered by the argillites of Waki

Source Rocks

  • Bituminous shales: Waki formation

  • Bituminous argillites and flubvio-lacustrine sandstone argillites

  • Lacustrine sandstone argillites: Kaiso formation

Traps

  • Structural traps

  • Stratigraphic traps

  • Tilted blocks

  • Faulted blocks in flower structure

Main Plays

  • Middle and Upper Miocene sandstone (Kisegi sandstone)

  • The fault formation of Garamba covered by the argillites of Waki


The seismic and drilling work carried out in the blocks adjacent to blocks I and II of the Democratic Republic of Congo, highlighted the structures in flower recalling on a small scale a system of collapse made of Horsts and grabens and which suddenly constitute safe from structural pitfalls.

Since the Albertine Graben is deeper in the Democratic Republic of Congo, it is assumed that trapping structures of large dimensions could contain economically exploitable reserves.

Albertine Graben main play types
Flowering faults in the Albertine Graben (Abeinomugisha, 2007)
Albertine Graben Basin Gravity Map