Posted on :Monday , 12th March 2018
Gas discoveries worldwide have outsized oil finds by a ratio of two to one over the past two decades. Led by ‘colossal’ finds in East Africa, Africa’s gas reserves have risen by some two-thirds in recent years. The continent’s proven gas reserves of 503.3 trillion cubic feet (Tcf) at end-2016 (BP data) were mainly concentrated in Algeria, Egypt, and Nigeria – accounting for 92 percent of aggregate.
The crown jewels are new players Mozambique and Tanzania boasting recoverable gas estimated at 180Tcf and 57Tcf, respectively. Further exploration and development in the prolific Rovuma Basin could see Mozambique overtaking Nigeria as Africa’s biggest holder of gas reserves.
The largest gas field in West Africa discovered by Kosmos, off the Senegal- Mauritania maritime border could be a game-changer. The Greater Tortue acreage contains over 50Tcf of resource potential – split roughly half between the two countries – and sufficient for 30-50 years of production.
Kosmos reported in January 2017 “After drilling to a total depth of 5,000-plus meters, the well found “101 meters of net gas pay in two excellent quality reservoirs”, which looks to be a “single, large gas accumulation”. UK-based Wood Mackenzie noted: “We think it’s a world-class asset with a good upside.”
Nigeria also boasts vast gas reservoirs, but not yet developed. The Nigerian National Petroleum Corp (NNPC) estimates probable reserves at 600Tcf, much of which lie in untapped deep and ultra-deep offshore terrain in the Niger Delta. It’s proven reserves are 186.6Tcf. Neighbouring Cameroon has more gas than oil, with a potential of 20Tcf, in the Rio Del Rey (covering 7,000km offshore) and Douala/Kribi-Campo Basins, covering 19,000km area. Angola and Gabon hold sizeable offshore oil-gas resources in the pre-salt acreage.
Wood Mackenzie believes South Africa possesses a lot of prospective offshore acreage with potential for future giant discoveries. Last September, PetroSA, and Rosgeo (Russian co.) signed a US$400mn deal to develop exploration areas off-South Coast of South Africa. The project – carrying out more than 4,000 sq km of 3D seismic operations and more than 13,000km of gravity-magnetic exploration works, as well as drilling exploratory wells – envisages producing 4mn cubic meters (cm) of gas daily as feedstock for PetroSA’s gas-to-liquids (GTL) refinery, in Mossel Bay.
“Discovery of hydrocarbons on our shores has the potential to bring significant revenues to the country and prove the country’s oil and gas prospectively,” noted PetroSA.
Additionally, the U.S. Energy Information Administration (EIA) estimates SA holds 390Tcf of technically recoverable shale gas resources, although estimates by the Petroleum Agency South African put the figure at conservative 40Tcf. The government has yet to issue any exploration permits for shale gas reserves in the semi-arid Karoo Basin, which poses logistical and environmental issues.
