THE last 4 or 5 years have seen an incredible amount of increased activity and interest in Tanzania's hydrocarbon (oil and Gas) industry - largely brought on by the announcements by companies like Ophir, BG, ENI and Statoil on the potentially very large gas discoveries being made in the deep water areas off the coast.
Numbers vary but the amounts of gas discovered offshore Tanzania alone range in the region of 30-90 Trillion Cubic Feet (Tcf) of gas (to put it into context: enough gas to power the United Kingdom for between 10 and 30 years!).
The deep water areas offshore Tanzania represents a significant hydrocarbon province in the country. The other areas are in the shallow coastal and landward areas and also the Interior Rifts.
These hydrocarbon provinces have been shaped during the geological evolution of Africa as a whole - but particularly in East Africa. A new player in the field of oil exploration in Tanzania is Swala Oil and Gas Tanzania Limited that was established in Dar es Salaam in July 2011 and is currently owned 35 per cent by and on behalf of Tanzania shareholders.
Its main shareholder, with 65 per cent is Swala Energy, an Australian company with assets in Sub-Saharan Africa and which is currently in the process of listing on the Australian Stock Exchange.
The company earlier this week announced that it would also be listing on the Dar es Salaam Stock Exchange on the Enterprise Growth Market (EGM) window by mid next month where each share would be sold at 500/- each. Swala Oil and Gas Tanzania Limited Exploration Director, Mr Neil Taylor said recently when he spoke to journalists that in spite of the huge oil and gas potentials that exist
in the country, there was a need for the public to be very patient because as is the nature of the industry, there were other things that come before production. "Since we started operations in 2012, we have made ground breaking explorations especially when you take in account that the areas that we operate in namely Kilosa and Pangani have never been surveyed.
Next year we plan to drill a well but it will take another couple of years before any production can be done," he said. The Pangani licence which covers 17,156sqkms, Swala was awarded a 50 per cent equity interest and operates the licence and is partnered by Otto Energy. The joint venture committed to carry out a certain work programme over a four-year exploration phase where in the first year, the partnership committed to reprocess and reinterpret historical data: to carry out a 3,000km airborne gravity-magnetic survey.
The results that were obtained after covering over 8000km of data suggest the presence of two-shallow basins, each of about 2000sqkm in area and they appear to be quite shallow although the uncertainties in the depth modeling from gravity and magnetic data allow for the basins to contain up to 2000m of Neogene sediments.
The Kilosa-Kilombero licence covering 17,675sqkm after conducting an airborne survey, the results confirmed that the presence of three basins, each of about 2000sqkm in area. The northern two basins at Kilosa and Kidatu probably contain up to 6000 or 7000m of sediment. "Most of the sediment is likely to be of Karoo age (100-260 million years) but there is potential for up to 2000m of Neogene fill.
The southern Kilombero basin potentially has a lesser fill of 2000 to 3000m but is likely to contain only Neogene sediments, it also exhibited anomalous stressed vegetation identified as being potentially caused by hydrocarbon escapes," Mr Taylor explained.
Giving some insight on the geological part of the country's potential, he said that there is a third target inside Tanzania which is the interior rifts. The interior rifts are particularly interesting in that they were created about 180 million years ago when a southern super-continent, Gondwana, started to break apart.
On the eastern side, the successful break-up ripped Madagascar from its old position next to Kenya. This also created the rift valley that stretches from Somalia to Lake Victoria, where it splits into Kenya and Tanzania and then follows the line of the great lakes - Albert, Edward, Kivu, Tanganyika and Nyasa - until it peters out in Mozambique.
This is the East African Rift System (EARS). Such rifts are often associated with hydrocarbons, as they are flooded and become rivers and lakes in which organic material accumulates. Over time this material is buried and cooked - if it is undercooked it produces coal; if it is over-cooked it generates gas; and if it is cooked just right it produces oil. "In the EARS, it was cooked just right.
A few years ago this was tested when oil was discovered in Uganda. Since 2012 it has been repeatedly tested in Kenya with the oil discoveries at Ngamia, Twigga and Etuko," he explained. Mr Taylor said that these are older rifts, predating the Gondwana break-up and that there were a number of them in the country and the age of the sediments meant that they are more likely to produce gas.
Swala Oil and Gas (Tanzania) Ltd are exploring both the EARS and the interior rifts in the two licenses that we currently hold: Pangani and Kilosa-Kilombero. Explaining how companies look for all this information, the expert said that they start by identifying the settings in which sediments could have been accumulated and by looking at them in greater detail to test whether they contain the right kind of rock, whether they are deep enough.
"After this they will typically carry out seismic surveys, where a sound is generated into the ground and specialist equipment listens for the sound waves as they are bounced off the underlying geology. Once the seismic data is cleaned up and processed it is interpreted so as to identify whether hydrocarbons can be trapped. The next step is to drill and test whether it does in fact contain hydrocarbons," he explained.
At present, different areas of Tanzania are at different stages: the offshore is relatively advanced and commercial plans are being prepared to exploit the natural gas that has been identified there.
AThe onshore and Lake Tanganyika are still under early exploration. The prospect of multi-billion dollar Liquefied Natural Gas (LNG) plants being constructed onshore to enable the gas to be sold overseas and also to provide domestic gas has catapulted Tanzania into the prospect of being a major hydrocarbon exporting nation. All in all these are exciting times for Tanzania (and Swala) onshore and offshore and for both oil and gas.