South Australia's Beach Energy Ltd. discussed the results of its 2012 inland offshore exploration program in western Tanzania in an investor presentation last month.
Wholly owned subsidiary Beach Petroleum (Tanzania) Ltd. holds 100% interest in a production-sharing agreement covering the 7200sq km Lake Tanganyika South Block. The company entered into the PSA with the Government of the United Republic of Tanzania and the TPDC (Tanzanian state petroleum corporation) on 23 June 2010.
New data acquisition
Later in 2010, Beach contracted with Fugro Airborne Surveys to acquire and process new airborne gravity gradiometer (AGG) and high-resolution airborne magnetic (H-RAM) data over the block, using the FALCON AGG system. The 27,000 line-km survey began 9 September 2010, and took about three months.
In June 2012, Fugro Oceansismica began acquiring the first 1800 line-km of the survey. Fugro converted a local ferry, MV Mwongozo, into a seismic acquisition vessel. The first survey was followed by an infill seismic program. .
In August 2012, it completed a new 2080 line-km 2D seismic data survey in the lake (map of 2D seismic lines at right, courtesy, Beach Energy).
Preliminary results confirm extensive structuring, similar to Lake Albert in Uganda. The company noted indications of hydrocarbons over tilted fault blocks, low-side rollovers, and mounded features.
Beach said that natural oil seeps in Lake Tanganyika and direct hydrocarbon indicators (DHIs) on the seismic data indicate a working petroleum system and the new data suggests potential for large discoveries (> 200MMbbl).
Interpreted Lake Tanganyika seismic section at right shows potential targets; red=gas, green=oil.
Lake Tanganyika is the largest lake in the East African rift system: 650km north-south and 1470m deep, with a volume of approximately 18,800cu km.
The first 2D seismic data in Lake Tanganyika was collected in 1983 by Project P.R.O.B.E. (Proto-Rifts and Oceanic Basin Evolution), a scientific consortium based at Duke University, Durham, North Carolina. Graduate students staffed the R/V Nyanja towing 4 airguns and a single streamer. Interpretation of the multifold seismic at Duke suggested 4km of sedimentary accumulation over bedrock in alternating half-graben basins, separated by accomodation zone highs.