Physical Landscape of the Albertine Rift System
The Albertine Graben forms part of the western arm of the Great Rift Valley system in East Africa.
Map 1: Albertine graben Geology
The Rift System is a unique physiographic region, comprising of the rift escarpments, the amorphous block of the Rwenzoris and an extensive Rift Valley or graben that extends in a north-east direction from the districts of Kanungu and Rukungiri at the border with the DRC, to the districts of Moyo and Adjumani at the border with the Sudan. . This Sensitivity Atlas covers an area of the Albertine defined by the boundary of oil exploration blocks which was established by Petroleum Exploration and Production Department (PEPD). The area includes the Rift Valley floor and the largest parts of the escarpment except in some parts of the rift stretch in the northern most and southern most parts of Lake Albert. In this latter area, the boundary of the exploration blocks excludes the rift escarpment.
The Albertine graben has several lakes including lakes Albert, Edward and George. These lakes were formed by intensive rifting in the geological past, which created depressions that were later filled with water. The valley floor also has a number of crater lakes all of which punctuate the generally variate and spectacular landscape of Rift Valley escarpments, the extensive Rift Valley and the towering block of mountains.
The Albertine area is a landscape of great relief contrast, with both the lowest elevation in the country of about 620m above mean sea level and the highest elevation in the country of about 5110m above mean sea level on the Magherita peak in the Rwenzori Mountains. The Rift Valley extends for a total distance of over 500 km with variable widths of 45-80 km (including part of the Democratic Republic of Congo).
Map 2: Map of Uganda showing location of the Rift Valley. (Source: Petroleum Exploration Production Department)
Trends in Oil Exploration in the Albertine graben
The petroleum potential of Uganda was first documented by A.J. Wayland in 1925, based on oil seepages he mapped at that time. The first well, Waki-B1, was drilled in the Butiaba area in 1938. The Albertine graben, the area with potential for petroleum accumulation, has since been subdivided into ten Exploration Areas. The Exploration Areas include blocks 1 and 5 located to the north of Lake Albert, blocks 2, 3A, 3B, 3C and 3D on and around Lake Albert, while blocks 4A, 4B and 4C are located around lakes Edward and George in the southern part of the graben. Five out of these ten Exploration Areas are licensed to oil exploration companies for exploration, development and production.
The map below shows the exploration areas:
Map 3 (Source: Petroleum Exploration Production Department, August, 2009)
Map 3 Source: Petroleum Exploration Production Department, August, 2009
Whereas the first phase of the Sensitivity Atlas focused on areas on and around Lake Albert where oil exploration and production activities were well advanced, this second phase covers other areas to where the activities have now been extended. Specifically, the second phase of the sensitivity mapping exercise will focus on updating the information provided in the first edition of the Sensitivity Atlas that was produced in 2009. It will also assess and map environmental sensitivities in the additional exploration areas including blocks 3B, 3C, 3D, 4A 4B and 4C.
Oil exploration and production activities so far indicate that the oil potential in this area is promising. For example, out of the 34 oil and gas wells that have been drilled, only 2 have been found without oil. Furthermore, the productivity prospects in the area are reasonably high; for instance the buffalo prospect alone can produce 400 million barrels of oil with an estimated revenue 15 times the Uganda’s current expenditure. The estimated reserves in the Albertine graben as a whole are about 2 billion barrels. The size of the reserves is enough to sustain production for 20 years.
The significant scale of oil discoveries as well as government policy on energy suggests the need for the construction of a fully fledged oil refinery, preferably within the exploration area. The preferred location of the refinery implies the need for construction of pipelines to transport crude and processed oil between the production wells, the refinery and later to the market outlets. The idea of a fully fledged refinery replaced earlier plans to construct an Early Production Scheme (EPS). The refinery is now deemed appropriate in view of the large size of oil reserves and large regional oil market. A consultant has, therefore, been hired to study the feasibility of the refinery. Some of the key issues in the study include the type, size, location and funding options of the refinery. The feasibility study will also include a preliminary environmental assessment of the potential environmental and social impacts of the proposed refinery. Furthermore, plans to commercialize gas production at Nzizi through use of the gas for power generation project are in final stages.
An Exploration site at Butiaba Runga village, Kapapi parish, Hoima District. (Source: Petroleum Exploration and Production Department (PEPD))
An Exploration site at Butiaba Runga village, Kapapi parish, Hoima District.
Source: Petroleum Exploration and Production Department (PEPD)