Africa Oil & Gas: Solo Oil reports Ntorya Appraisal Area major resource upgrade offshore Tanzania

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Rovuma PSA (Source: Aminex)

Solo Oil has announced that in collaboration with operator, Aminex, it can report a material increase in its estimate of gas initially in place (‘GIIP’) associated with the Ntorya gas-condensate discoveries in the Ntorya Appraisal Area, Tanzania.

The potential of the Ntorya Appraisal Area, which comprises approximately 750 square kms of the Ruvuma Petroleum Sharing Agreement (‘Ruvuma PSA’), has now been successfully tested by two gas wells; Ntorya-1 and -2.

Ruvuma PSA (Source: Aminex)

Following the Ntorya-2 well the Company now considers that the Ntorya Appraisal Area contains proven mean gross GIIP of 466 billion cubic feet (‘bcf’), a three-fold increase over the previous estimate of 153 bcf which was independently audited by LR Senergy in May 2015, prior to the drilling of Ntorya-2.


  • Mean gross GIIP increased by 200% from 153 bcf to 466 bcf
  • High estimate gross GIIP increased by 240% from 332 bcf to 1.13 tcf
  • Most likely gross Contingent Resources (2C) increased by 165% from 70 bcf to 186 bcf (Solo estimate)
  • High estimate gross Contingent Resources (3C) increased by 230% from 232 bcf to 766 bcf (Solo estimate)

These new Solo contingent resource estimates cover the Ntorya Appraisal Area only and do not include the potential of the adjoining Ruvuma PSA exploration licences which is also being reassessed.

Neil Ritson, Solo’s Chairman commented:

‘The Ntorya-2 well, in conjunction with the existing well and seismic control, allow a new more confident and upgraded estimate of the gas in place and the associated contingent resources associated with the successful appraisal well.  As a result Aminex is currently applying for a 25-year development licence and is working directly with the Tanzanian Government on means to fast-track gas production.’

The upgraded estimate follows the drilling and testing of the Ntorya-2 appraisal well earlier this year which encountered a net pay zone of 31 metres and tested gas at an average flow rate of 17 million standard cubic feet per day (‘mmscfd’) (approx. 2,830 barrels oil equivalent per day) through a 40/64-inch choke. The previous well, Ntorya-1, was tested at a rate of 20 mmscfd through a 1-inch choke.  Solo believes that higher flow rates can be achieved at Ntorya-2 during future production once the drilling induced formation damage is removed.

According to the interpretation of the wireline logs, Ntorya-2 encountered the equivalent reservoir section seen in the Ntorya-1 well at a depth approx. 74 metres shallower.   No formation water was produced during the tests.  The fluids recovered down-dip at Ntorya-1 showed a higher condensate-gas ratio and this suggests some fractionation of fluids with depth, further suggesting an extensive gas column is present with in the Ntorya gas-condensate accumulation.

Ntorya-2 also encountered traces of oil in the gross reservoir interval.  Aminex is currently updating the basin model in order to optimise future drilling to maximise the intersection with the reservoir section and to target potentially liquid hydrocarbon bearing reservoirs in future wells, including Ntorya-3. Outside the Ntorya Appraisal Area LR Senergy estimated 3 tcf of gross mean undiscovered GIIP in the Ruvuma PSA and that remains to be further evaluated.

Solo owns a 25% non-operating interest in the Ntorya Appraisal Area, the Ruvuma PSA, and the Ntorya-1 and -2 wells, which are operated by Aminex.(source: Solo Oil)

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