Orca Exploration Group operates one licence in Tanzania which comprises two blocks known as the Discovery Blocks. The license has a total area of approximately 41,630 acres (170 km2). The blocks are located in shallow water approximately 15 kilometres off the coast and 200 kilometres south of Dar es Salaam. The license contains the large Songo Songo gas field which is positioned on and slightly offshore Songo Songo Island (SSI). The main reservoir is developed in Lower Cretaceous aged Neocomian to Albian sandstones (Neocomian), while Upper Cretaceous aged Cenomanian sands that lie unconformably on the Lower Cretaceous provide additional reservoir when developed.
As at 31 December 2011 the independent reserve evaluator, McDaniel and Associates Consultants Limited, assessed the Additional Gas proven (1P) and proven and probable (2P) Songo Songo reserves available to Orca to the end of the licence period at 469 Bcf and 584 Bcf respectively. Orca management estimates that the total Mid Case reserves (Protected Gas plus Additional Gas) from the Songo Songo Field and the Songo Songo North discovery is 1,079 Bcf as at 31 December 2011.Orca operates a gas processing facility on SSI on behalf of Songas Limited (Songas) on a no loss, no gain basis. The plant supplies natural gas to a 25 km 12" offshore pipeline and a 207 km 16" onshore pipeline and is used by the power sector and industrial markets in the Dar es Salaam area. Songo Songo was Tanzania's first natural gas development.