Tanzania has had more success in its search for gas than for oil. Two major gas finds at Songo Songo and Mnazi Bay are due to be developed in the Songo Songo Gas to Electricity Project.
Songo Songo was Tanzania’s first important hydrocarbon discovery in which gas from Lower Cretaceous sands tested up to 23 million cubic feet per day of gas and minor volumes of high API oil. Seven appraisal wells have been drilled and reserves are estimated to be about 1Tcf. Although the gas is methane-rich, ethane and higher hydrocarbons are ubiquitous. Gas ratios are characteristic of gases associated with oils and several wells in the field have tested 42 to 50 degree API condensate. Biomarker analysis conducted on the condensate indicates derivation from moderately mature type II/III kerogen.
Mnazi Bay-1 tested gas at rates up to 14 million cubic feet per day from Oligocene sands. No appraisal wells have been drilled to date but reserves are calculated also to be approximately 1 Tcf. This gas is almost entirely composed of methane and is thought to be mainly biogenic in origin.
Songo Songo Gas to Electricity Project
The Songo Songo gas project is likely to be operational in 2003 with gas onstream. Pan African Energy (previously Ocelot) is the operator on the project. TransCanada PipeLines Limited who were previously involved in the project sold their interest to AES Tanzania Holdings Limited (AES) in 2000. The project has been in progress for close on twenty years. The two companies involved are working closely with the Government of Tanzania, the World Bank, the European Investment Bank and the CDC Group plc to reach final closure of the first stage of the project by the end of the year 2000. The construction phase of the project is due to start early in 2001.
A power purchase agreement with the Tanzania Electric Supply Company (TANESCO) and gas sale to a cement plant will be important factors in underpinning the development. There are plans to distribute gas to other markets. Upside reserves are 1 Tcf with recoverable estimated at 500 Bcf. The five wells will be able to produce at a rate of 100 million cubic foot of gas per day.