African exploration specialist  Ophir Energy has claimed a new play- opening Cretaceous deepwater discovery offshore Tanzania with the Papa 1 exploration well.

Papa 1 has encountered up to up to 89 metres (291 feet) of gas in an Upper Cretaceous zone and based on preliminary data, Ophir has suggested that the find could contain between 0.5 and 2 trillion cubic feet of gas.

London-listed Ophir reported today that the well, drilled as part of joint exploration venture with Britain’s BG Group,  was drilled just outside the Rufiji Delta region in block 3 offshore Tanzania, and it makes the sixth consecutive discovery for Ophir in the country.

The find is 100 kilometres (62 miles) offshore from the Tanzanian mainland in block 3, and  53 km  (33 miles) south-east of the previous Pweza-1 discovery. The well was drilled by the Deep Sea Metro drillship, operating in a water depth of 2186 metres (7,170 feet), to a total depth of 5544 m (18,184 ft) in 57 days.

Ophir’s chief executive Nick Cooper explains why Papa 1 is so significant: “The two most recent wells in Tanzania were designed to test the deeper-lying prospectivity of the Cretaceous Intraslope play,” he stated. “The Mzia-1 success in May 2012 confirmed for the first time the prospectivity in the Upper Cretaceous sequences outboard of the Rovuma Delta.  The Papa-1 success now confirms similar Upper Cretaceous prospectivity outboard of the Rufiji Delta and represents the first discovery in Block 3.”

And he went on: “While recoverable resources are likely to be lower than pre-drill estimates, this very encouraging discovery is expected to lead to substantial additional resources from this new Upper Cretaceous play.

Further detailed petrophysical and core analysis will commence shortly to calibrate the logging data and refine the in place and recoverable resource estimates, Cooper’s company indicated.

Ophir says the Papa discovery de-risks a deeper Upper Cretaceous Intraslope play in Tanzania:  “Additional resources have now been discovered in the Cretaceous stratigraphy outboard of both the Rovuma and Rufiji Deltas by the Mzia-1 and Papa-1 wells. An update of the in place and recoverable resource estimates from the Mzia and Papa discoveries on the new Cretaceous Intraslope play will follow the ongoing petrophysical analysis,” Ophir adds.

The first four discovery by the Ophir BG joint venture have tested Miocene, Oligocene and Paleocene age targeted in a Tertiary Intraslope play. Together they are currently estimated to have discovered total recoverable resources of 7 tcf – 1,167 m boe. The fifth discovery, Mzia, and the sixth discovery, Papa, both in the new Upper Cretaceous Intraslope Play are expected to add considerable additional recoverable resource to this total, Ophir states.

Next, the Deep Sea Metro is to be sublet to Apache for a well in block L8 offshore Kenya, next to Ophir’s block L9, before it returns to continue drilling for the Ophir-BG joint venture, where the drillship is to spud a well in block 1 offshore Tanzania, due in October. Ophir and BG are planning  two step out exploration and appraisal wells near the Jodari discovery to firm up that 3.4 tcf (567 m boe) discovery for a possible LNG hub development.