The petroleum exploration database in Tanzania consists of numerous geological and geochemical studies, geological and drilling records from more than 100 boreholes and 45 deep wells with status and many thousands of kilometers of gravity, airborne magnetometer, and seismic surveys. A summary of each well, a full list of electric logs, mud logs, geological and engineering reports, and composite logs are available for inspection at TPDC's Exploration Office in Dar es Salaam. Several technical reports have been prepared from these data and provide an assessment of the hydrocarbon potential of Tanzania. Data packages for each of the exploration areas are also available for purchase.
Geology and Surface Information:.
The country was initially mapped by the Tanganyika Geological Survey, based in Dodoma, and geological maps are available at a scale of 1:50,000. The sedimentary basins of Tanzania cover nearly 500,000 square km both onshore and offshore. Nearly fifty (50) wells have been drilled providing crucial subsurface geological information and knowledge on the petroleum prospectivity of the different basins. Gas has been discovered in numerous areas and is been produced from Songo Songo and Mnazi Bay. The whole country has been covered by topographic maps available in convenient scales of 1:100,000, 1:250,000 available from the Government mapping department.
Magnetic And Gravity Surveys:.
There is excellent coverage of aeromagnetic data over Tanzania. Onshore and offshore, the data include magnetic surveys of 1971 by Aerosurvey for AGIP and a 1976 survey by Geosurvey International for the Government. The data from these surveys are in the form of maps and are available for inspection at the TPDC offices. The coverage of gravity data is 'patchy', consisting mainly of regional surveys. The best coverage is in the coastal area over the Mandawa and Ruvuma basins, the larger offshore islands and in the Rukwa Rift Basin. In the Ruvu, Selous and Rufiji areas the gravity coverage is limited mainly along the recently acquired seismic lines
More than 100,000 time line of 2D seismic data has been acquired over the years both onshore and offshore. 3D seismic data has also been acquired, mainly offshore. Details of all seismic surveys with a listing of acquisition and processing parameters and a shot point map at a scale of 1:500,000 are available. Most of these data can be obtained in the form of paper prints and films. A certain amount of digital is also available. Efforts are currently underway to have all old seismic data and reports in electronic form.