- Home
- Conferences
- Conference Proceedings
- Conferences
Second EAGE Eastern Africa Petroleum Geoscience Forum
- Conference date: November 22-24, 2016
- Location: Kampala, Uganda
- Published: 22 November 2016
-
-
Planation Surfaces of the East African Rift as a Record of Vertical Movements and Denudation Measurement Since 60 Ma
More LessSummaryThe objective of this presentation is (1) to reconstruct the different steps of the East African Rift growing and mainly the domes, (2) to discuss their relationships with mantle dynamics and (3) to use planation surfaces for measuring the denudation through time (volume of eroded sediments incoming in sedimentary basins).
The African relief – including the East African Rift Domes - results from two major types of planation surfaces, etchplains (weathering surfaces by laterites) and pediplains/pediments. These planation surfaces are stepped along plateaus with different elevations. The stepping of the pediment-type planation surfaces records a local base level fall due to local uplift.
The present-day topography of the East African Rift is younger than 40-30 Ma. (1) The very long wavelength uplift (1000–2000 km) of the East African Dome started around 34 Ma (Eocene-Oligocene boundary). (2) The uplift rate increased during Late Miocene times (11-6 Ma) with the incision of large pediplains well dated on the Congolese side of the East African Dome.
-
-
-
The Lake Albert Rift (Uganda) - Sediment Budget, Deformation, Basin and Relief Evolution Since 17 Ma
Authors B. Simon, F. Guillocheau, O. Fauteuil, C. Robin, T. Nalpas, P. Pickford, B. Sénut, M. Bez, P. Lays and P. BourgesSummaryThe measurement of deposited volumes of sediments is based on the basin infilling study which consists on both subsurface data and outcrops analysis. The main objectives were (1) to obtain an age model based on onshore mammals biozones and (2) to reconstruct the 3D architecture of the rift using sequence stratigraphy correlations and seismic data interpretation. Deformation evolution of the rift through times is characterized according to seismic interpretation and to the distribution and quantification of the accommodation for several time intervals. Two major unconformities were identified and dated at 6.2 Ma (Uppermost Miocene) and 2.7 Ma (Pliocene-Pleistocene boundary), coeval with major subsidence and climatic changes.
The landforms analysis is based on the characterization, relative dating and 3D mapping of Ugandan landforms which consist of stepped planation surfaces and incised valleys.
The sediment budget is successful with, between 17 and 2.5 Ma, an excess of 16 % of upstream eroded material compared to the sediment volume deposited that can be explained by the chemical erosion prevailing at this period in Central Africa. The significant (60%) opposite difference between 2.7 and 0 Ma may be the consequence of a high sediment supply resulting from the erosion of the uplifted Ruwenzori Mountains.
-
-
-
Characterizing Thin Sand Reservoirs in Onshore Uganda - Challenges and Lessons Learned
Authors M. Giboli, A. Lafram, M. Beele, H. Tsaralaza, A.S. Barnola and J. NduggaSummaryThe study area is located onshore North West of Uganda. It contains significant oil and gas reserves in numerous narrow river channels, whose appraisal has been realized so far using vertical wells, thus within a high risk of bypassed pay. The objective is to succeed in mapping sands down to 3–5 meter which are part of the multi-level 3D fluvial channel system and be able to identify hydrocarbon distribution within these sands. The study area presented several challenges for characterizing thin sands and also mapping the sand distribution. Despite the very shallow geological setting with several unconsolidated sand units, a poor seismic-to-well calibration, overall medium to poor quality of available log data and limited spectral overlap between angle-stacks, results of a deterministic inversion and dedicated classification could still be helpful for improving sedimentological model and reservoirs distribution understanding. By preserving the high frequency information thanks to an extensive denoise sequence it was possible to successfully delineate the geometry of thin hydrocarbon bearing sand reservoirs. Comparison with coloured inversion results led to the conclusion that a simultaneous seismic inversion should provide extra added value in terms of reservoir characterization compared to a simpler method working separately on different angle-stacks.
-
-
-
DRC TOROKO (Block 3) - Onsite Processing QC Benefits on a 2D Land Seismic Acquisition
Authors FC Chasserot, H.L. Lancien, O.D.P. de Pellegars and C.C. ChappeySummaryEarly 2016, Total EP RDC lead a 2D land seismic survey on the north part of the Block 3 in the north east Democratic Republic of Congo. This acquisition was performed by Tesla Exploration and represents 16 2D lines for a total length of 246 km. The complexity and difficult context of the DRC’s block 3 constrained Total to adapt the acquisition design and setting. An innovative approach has been applied to face the unfriendly field and HSE constrain. The onsite processing QC take place in this context where regular methods met theirs limits.
In addition to have the data immediately available, the processing presence onsite during meeting or on the operation site gives a real creative force and avoids lag between advice and operation. It gives the concrete information to be able to take the right decision considering all the practical and geophysical aspects.
-
-
-
Application of Spectral Decomposition for Delineation of Reservoir Architecture in the Kigogole, Nsoga, Ngege Complex, Buliisa, Uganda
Authors T. Redondo-Lopez, A. Jagger and S. CotterilSummarySpectral Decomposition of a high quality seismic data has resulted on high definition images of the Kigogole, Nsoga, Ngege Complex, Buliisa, Uganda. These images have provided an improvement in the sedimentological understanding, and contributed to the modelling of its reservoir distribution. Spectral Decomposition analysis has proven to be a fast, efficient and insightful method of reservoir architecture delineation.
-
-
-
Capacity Building for National Exploration Risk and Resource Assessment Programs
Authors B.P. Wygrala, T. Levy and R. Thabang SegageSummaryPetroleum Resource Assessments, which quantify and demonstrate the overall potential of a prospective area or country, are essential to a Government’s efforts to effectively evaluate and market their petroleum resources and to get them explored and ultimately produced. A rigorous Petroleum Resource Assessment is, therefore not only an academic or scientific effort, but an essential tool for a national agency to manage the country’s hydrocarbon wealth.
The authors present capacity building programs which enable regulatory authorities to more completely understand the true potential of the areas offered, so that the agency can set terms that will get fair value for the country from any hydrocarbons that are discovered, to decide which areas to offer that are most likely to attract investment, and to present a technical prospectus that will convince investors that the areas being offered have significant hydrocarbon potential AND are superior to other areas inside or outside the country that may be in competition for investment funds.
-
-
-
The significance of Technical Collaboration Between Makerere University, Oil Companies, the Government and other Universities
More LessSummaryUganda has proven oil reserves of about 6.5 billion barrels that have been discovered in the Albertine graben of the western Arm of the East African Rift System ( PEPD., 2013 ).
In 2009, the department of geology and petroleum studies at Makerere University introduced a BSc. Programme and later a MSc. Programme (2012) in Petroleum Geosciences in Petroleum Geoscience and Production. This came at a time when Uganda had discovered enormous recoverable oil and gas reserves and there was an urgent need for a skillful national enterprising capacity to work in the future oil industry when production commences. This is in line with Uganda’s National oil and Gas Policy of 2008 on development and maintaining of national skills and expertise.
Because the petroleum industry in Uganda is fast expanding, there is a strong need to build capacity at the institutions of higher learning in order to fill the human resource capacity gaps for both public and private sectors.
Therefore since the course was introduced at Makerere University, the department of geology and petroleum studies has in its capacity forged relationships with both the government (The Ministry of energy and mineral development and the Petroleum Exploration and Production Department, PEPD), Norwegian government, oil and gas companies like CNOOC, TOTAL E&P, Tullow oil and Schlumberger a service company.
The collaboration has positively enriched graduates with skills that are relevant in the national oil and gas industry as they are equipped with knowledge in geoscience software, practical exploration techniques, health and safety geology, petroleum geochemistry, petroleum economics and reservoir engineering.
-
-
-
Are Geological and Geophysical Data of the Albertine Graben, Big Data? Are they Big in an Integrated Upstream Project?
Authors S.L. Nimmagadda, A. Ochan and A. RudraSummaryIn spite of high pace of exploration activity in the Lake Albert basin, appraisal and field development become challenging in the Albertine Graben of Western Uganda. The volumes and variety of exploration data sources in these basins exist in different scales, sizes and formats in multiple dimensions (including periodic and geographic dimensions) and domains. Modelling and integrating such unstructured data need a new direction, in particular, the data structuring, storage and retrieval. We propose Big Data tools since the data in terabyte scale in multiple domains are needed to bring them together in an upstream business. We aim at a holistic information system development, simulating Petroleum Digital Ecosystem (PDE) and Petroleum Management Information System (PMIS) articulations with data modelling, data warehousing and mining, visualization and interpretation artefacts. This approach facilitates the data management not only in the Albertine Graben but from basins of Sudan, Uganda, Kenya, Tanzania, Rwanda and Burundi in the western arm of the East African Rift System (EARS). We evaluate Big Data, exploring the connectivity among multiple oil and gas fields and their associated petroleum systems, providing new insights on data integration and management, adding values to data analytics and exploration projects in the Albertine Graben context.
-
-
-
Lake Tanganyika - Geological Evolution and Potential Hydrocarbon Plays
More LessSummaryLake Tanganyika is an NNW-SSE trending lake on the border of DRC and Tanzania and is one of the basins of East African Rift System. It is over 700 km long, approximately 50 km wide and up to 1500 meters deep. Its structural evolution is best explained as pull-apart basins that developed along pre-existing weaknesses of the Proterozoic belt, in an E-W extensional stress regime. Lake Tanganyika can be expected to display sedimentation patterns that are typical of rift basins. Slicks are observed in Lake Tanganyika and are an indication of the presence source rocks. Based on geological observations, it can be concluded that Lake Tanganyika has the key elements to make it a prospective hydrocarbon basin.
-
-
-
The Exploration History of East Africa
By D. MacgregorSummaryEast Africa has emerged as one of the new and exciting petroleum provinces of the 21st Century. This success is, for the most part, a relatively recent event and comes after many decades of relatively unsuccessful exploration. This paper looks at the exploration play concepts that have both led and misled the search for oil and gas deposits in the region over those years by plotting wells and discoveries through time on a series of simple fairway maps. Understanding the exploration legacy of this region is shown to be key. Most discoveries had pointers towards them from early drilling in terms of discoveries that may have been uneconomic at that time, proven source rocks or columns which must have been charged from distant kitchens. Associated with this, the distribution of working trap types does not follow global paradigms. Fields in simple four way closures are rare in east Africa and instead we see a high stratigraphic or downthrown element in the offshore traps and largest onshore gas fields, and unusual fault sealed and downthrown traps in the EARS.
-
-
-
Tectonics and Petroleum Systems of East African Rifts
By D. MacgregorSummaryEast Africa represents the most rifted portion of crust on the planet. The first rift phase commenced in the Permian as the ‘Karroo’ set of half grabens In Kenya and Ethiopia. These propagate into a set of younger rifts with peak rifting phases in the Early Triassic.
A further phase of rifting is seen in the Early Jurassic, concentrated along what will later become the East African passive margin. This phase ends in the Kimmeridgian break-up between Africa and Madagascar. A Late Jurassic rift population also extends from Yemen across to Somaliland. Another population of latest Jurassic-earliest Cretaceous age is interpreted in onshore and offshore southern Mozambique.
Multiphase Cretaceous rifting is concentrated along NW-SE trends. A focus in recent years has been the Anza Graben of Kenya, where events do not correlate well to the Sudan rifts.
The East African Rift System (‘EARS’) commenced in the Lokichar Basins of northern Kenya in the Late Eocene to Oligocene. At various times during the Mid-Late Miocene, a series of small rifts and depressions formed between Ethiopia and Malawi, heralding the main regional rift subsidence phase and further rift propagation in the Plio-Pleistocene.
-