The North Rukwa Project is the Company’s flagship project located in the Rukwa Basin in southwest Tanzania, which comprises twelve granted Prospecting Licences (PL) covering a combined area of approximately 1,467km2.
The North Rukwa project area is accessible by road via the TANZAM highway from Dar es Salaam to Mbeya at the southern end of Lake Rukwa, followed by regional roads north, to Sumbawanga on the western side of Lake Rukwa and to Gua on the eastern side of Lake Rukwa.
Figure 1. North Rukwa Helium PLs and Leads to date
Review and analysis of mud-gas readings obtained during the drilling of Mbelele-1 clearly indicate helium readings significantly above background from around 75m to 125m (see Figure 2). Further, recently completed reservoir modelling demonstrates the potential for commercial flow rates from this part of the Mbelele structure.
Lab results have previously confirmed high helium concentrations up to 2.46% at Mbelele. The next step is to perform a low-cost test on Mbelele-1’s shallow section, where downhole samples using the Modular Dynamic Tester (MDT) could not previously be acquired. Results will inform both early commercialisation opportunities and future, deeper, potentially richer targets.
Figure 2. Mbelele-1 Mud-logs – elevated Helium readings, highest concentrations in ‘gas cap’ zone.
Table 1. Reservoirs encountered in the Upper and Middle Lake Beds at Mbelele-1 (wireline porosities).
Table 2. Lake Beds Reservoirs encountered in the 8.5” section at Mbelele-2 (wireline porosities).
Noble plans to drill an off-set well to Mbelele-1 to test the identified probable free gas zone. The Company will be drilling to a depth of approximately 125m using a specially designed well-head that will allow it to undertake all the required test work.
A simple mobilisation and de-mobilisation method will be used, with the Company in the process of contracting a low-cost Tanzanian drilling rig. The University of Dar-es Salam have been engaged to undertake on-site testing. The drilling program is planned for H2 2024.
A team from the University of Dar es Salaam School of Mines and Geosciences has completed shallow seismic and is preparing to undertake electrical resistivity surveys to confirm the targets and mature them to “drillable” status as part of the upcoming appraisal program. data processing, interpretation and integration of the initial priority area shallow seismic data is now underway, a further step towards high-grading targets for the upcoming shallow drilling program.
As the survey work is completed at each location and the results are integrated into our sub-surface model, the Company will finalise the new drill locations and landowner arrangements, then mobilise the rig to site. It is expected that each well will take approximately 2-3 days to drill with approximately one week of testing to follow while the rig is relocated to the next site.
The Company is having specialised well heads manufactured to allow for gas flow and composition testing using a methodology adapted from the successful shallow helium well tests undertaken by 45-8 Energy a private French Helium exploration and production company.
The first three drill sites have been selected out of 10 potential shallow gas targets stretching from north to south along North Rukwa’s western margin.
Figure 3. Western Lake Bed Zone – additional potential free gas Helium targets.
Independent resource auditors Netherland, Sewell & Associates, Inc (NSAI) of Houston has completed an update of the Western Margin of the North Rukwa basin, as stage 1 of a full portfolio review.
Table 3. North Rukwa Western Margin Prospective Resources.
