Shale Oil and Gas in East Africa (Esp. Tanzania), with New Ideas on Reserves and Possible Synergies with Renewables
Shale oil and gas in East Africa, with new ideas on reserves and possible synergies with renewables Shale oil and gas production have lately revolutionized the oil and gas industry as a real “game-changer”, especially in the US. This has prompted many companies and governments to search for these unconventionals with successes in the UK, Poland and Argentina. These unconventionals do often occur onshore in places, where there is no conventional hydrocarbon production, thus enabling the local government or companies to have a new energy source, which is especially valid in Onshore East Africa. New drilling technologies, which combine shale and geothermal drilling/production, are now being developed. Now it is possible to drill/produce both unconventionals and geothermal from a single well. Gas and oil could be produced from the central pipe, and hot water from the outer tubing, thereby reducing development cost for both methods. In Tanzania a study was performed to look at unconventional oil and gas resources in sedimentary basins. A lot of data on Karoo geology, maturity, TOC's and volumetrics will be presented. In general, one needs a thick sedimentary basin with a lot of shales, good maturity and TOC values, and a fairly unfaulted basin to prevent seismicity when fracking. In East Africa and Southern Africa at large only the Karoo sediments of Permian/Triassic age are a suitable candidate for large shale oil/gas reserves. The possible large Karoo shale gas development in South Africa is a good example. A large heavy oilfield at surface in Madagascar proves an oil source in the Karoo. In S.Kenya and also on Pemba oil shows are known, with a unknown Pre-Jurassic source. Preliminary resource calculations in Tanzania indicate possible resources in place of 50-200 Tcf of gas for the Selous basin, comparable in size with the South-African Karoo Basin. The depth of the source rocks make gas the most likely hydrocarbon phase. One has to note that calculating unconventional resources is much more complicated than with conventional resources, since the adsorbed gas (or oil) needs to be calculated from core or log analyses. An onshore well could also text the synergies with geothermal drilling. Recently, TPDC in Tanzania has started a new evaluation, based on new mapping, rock analyses and maturity studies, into the shale oil and gas potential.
AAPG Datapages/Search and Discovery Article #90267 ©2016 AAPG/SPE Africa Energy and Technology Conference, Nairobi City, Kenya, December 5-7, 2016