US oil explorer Apache has begun drilling oil in a block situated off the Kenyan coast, becoming the second firm to sink an offshore well in the country after Australia's Woodside Petroleum.

Apache, which owns 50 per cent of the L8 exploration block, is the lead operator of the block and is expected to conduct drilling to a depth of 3250 metres below the sea surface over the next 60 days.

“Origin energy advises that L-8 operator Apache Corporation has, on behalf of the joint venture commenced drilling the Mbawa prospect in Kenya.

The Mbawa 1 exploration well spudded at 6.00hrs local time on 10 August 2012,” Origin Energy—one of Apache partners in the oil block said in a statement to the Australian Securities Exchange(ASX) on Monday.

Origin Energy owns 20 per cent of the block, while Tullow and pancontinental Oil equally share the remaining 30 per cent.

“The well has reached a depth of 1519 metres below the drill floor and casing is currently being set. Drilling will recommence once the casing has been completed,” pancontinental said in a statement on Monday.

Pancontinental oil estimates that the block could contain as much as 4.9 billion barrels of oil, though Morgan Stanley – the global research firm -estimates that only 20-30 per cent of the oil is actually recoverable.

Woodside had in 2007 spend $100 million to drill Kenya’s first offshore well but on the L5 block situated in the Lamu basin but the well turned out to be dry.

Mbawa sits in the Lamu Basin which extends offshore Kenya, and has generated considerable interest particularly after successive gas discoveries to off the coast of Tanzania and Mozambique which share the same geological characteristic with the Kenyan coast.

However, despite the gas discoveries in the two countries the oil exploration firms the Kenyan coast could be oil prone.

“While other locations are proving to be ‘gas prone’ along the East African margin, Pancontinental believes there is an extensive oil prone ‘sweet spot’ offshore Kenya,” the company said in a statement.

Apache has identified the Tai prospect as an exploration follow up if the Mbawa 1 well proves successful. The East African region has off late witnessed considerable gas and oil interest after gas discoveries in Tanzania and oil discovery in Uganda and Kenya.

Fresh from its recent oil discovery in Turkana, Tullow oil is expected to drill three more wells in Kenya this year. Analysts as Jefferies research group say the firm will drill Twiga South and North wells this quarter while it is expected to drill the Paipai well in the fourth quarter of the year.