Statoil and ExxonMobil discovered gas in the Mronge-1 well, bringing total in-place volumes of gas on the block to 17 trillion to 20 trillion cubic feet of gas.
The well discovered gas at two levels, with the main accumulation in the same level as in the Zafarani-1 well on the same block.
The Zafarani-1 well was drilled in 2012 and opened up the block for further exploration.
The other accumulation was found in a younger gas bearing reservoir which had not previously been tested.
The find was preceded by three high-impact gas discoveries made during the first drilling phase.
Statoil senior vice president exploration activities Western hemisphere Nick Maden said these were high value resources off the coast of Tanzania.
“The discoveries also demonstrate how Statoil’s strategy of focusing on high-impact opportunities is paying off and supports the company’s ambition for international growth,” he said.
Tanzania Energy and Minerals Miniter Sospeter Muhogo said the Tanzania government was pleased to learn about the extra gas resources off the country’s coast.
The well was drilled with the drillship Discoverer Americas. After the company finishes at Mronge-1, it will appraise the 2012 Zafarani discovery.
Statoil has a 65% working interest in the block, while ExxonMobil holds the remaining 35%. The company was awarded the block in 2007.