The partnership of BG (operator) and Ophir have confirmed an important new gas discovery in deepwater Block 1, Tanzania. Drilled using the ‘Deepsea Metro 1’ drillship, the Taachui 1ST well, close to the western boundary of the block, was sidetracked for operational reasons and was drilled to a total depth of 4,215m. The well encountered net gas pay of 155m within Lower Cretaceous clastics as expected, while the gross column reached 289m. It flowed gas at a stabilised rate of 14MMcfpd and mean recoverable reserves are estimated at 1Tcf. The size of the gas column is such that the discovery could extend into a second compartment to the west which has the potential to be of a similar size. An appraisal well to confirm this upside and is under consideration by the JV partners.
The result extends the proven hydrocarbon system to the eastern limit of, and partly de-risks, Ophir’s East Pande permit on which the Tende 1 well will be drilled in 680m of water later in 2014. In addition, the aggregate recoverable volumes of around 16.7 Tcf are now approaching the threshold needed to underpin a potential third LNG Train from Blocks 1, 3, and 4. A drilling success at Tende would de-risk two further prospects within the block, Balungi and Ndimu, which could add almost 2.5 Tcf of natural gas reserves in the Block.
On the downside, Tanzania’s hopes of becoming an exporterof natural gas face fresh delays after the country’s opposition refused to participate in further talks to rewrite the constitution. The delay prolongs the constitutional uncertainty over whether the semi-autonomous government of Zanzibar can sign its own exploration deal and thus secure all the revenues. The country was due to put a new constitution to a popular referendum next year but the opposition boycott and several missed deadlines mean the new law is unlikely to be approved before presidential elections scheduled for October 2015.
