NAIROBI, Feb 24

China's CNOOC has drilled 4,456 metres of its Boghal-1 well in Kenya's Block 9 and has not made any discovery yet, the National Oil Corporation of Kenya said on Wednesday.

CNOOC spudded the $26 million exploration well in northern Kenya in October. It will be the deepest yet in east Africa's biggest economy, a country that has searched in vain for commercial oil and gas deposits for decades.

"There is no discovery yet, but the target depth is 5,556 metres," National Oil Managing Director Mwendia Nyaga told a news conference. "We are still hopeful because the target depth is still a kilometre away."

"No hydrocarbons have been found yet," he said.

In October, Kenyan Energy Minister Kiraitu Murungi said Boghal-1 would pass through two possible hydrocarbon horizons, at 3,000 and 5,000 metres.

Kenya has 36 blocks, of which 23 are leased, said National Oil, a state-owned with upstream and downstream activities.

CNOOC, which is in the chase for a chunk of Uganda's oil reserves, has two blocks.

The Boghal-1 well in Block 9 of the Anza Basin is the 32nd drilled in Kenya, which hopes to capitalise on growing interest in the continent due to high oil prices and increasing energy nationalism elsewhere in the region.

Kenya says out of the 31 wells already drilled, 19 have shown hydrocarbons.

"We have very positive indicators," said Peter Thuo, head of exploration at National Oil, mentioning the Loperot-1, Sirius-1 and Pate-1 wells.

In exploration terms, east Africa lags far behind the other regions with fewer than 500 wells, compared with some 14,000 in west Africa and nearly 20,000 in north Africa.