Royal Dutch Shell yesterday defended deep-water oil drilling as it announced a near-doubling of its second-quarter profit and a beefed-up target for asset sales.

Peter Voser, Shell chief executive, said BP's Gulf of Mexico deep-water oil spill was a tragedy but Shell had so far seen no need to change how it operated prior to the release of the accident investigation findings.

Deep-water drilling still had an important role to play in global energy supply. “We have got growth potential there,” he said.

Mr Voser also declined to rule out taking legal action against BP over the post-spill regulatory crackdown, which has cost Shell tens of millions of dollars.

Shell's second-quarter profit rose 94 per cent to $4.53bn on a current cost of supplies basis, a closely watched post-tax measure that removes the effect of price changes on inventories.

Underlying CCS profit – a measure that further strips out one-off items – was $4.21bn, beating analysts' expectations.

The one-off items included a $56m charge resulting from a deep-water drilling moratorium in the Gulf of Mexico and a delay to exploration in Alaska.

Seven Shell rigs are being kept idle as a consequence of the two measures, imposed after the spill.

BP, Shell's biggest UK rival, reported a $17bn second-quarter loss on Tuesday and has suspended dividends because of the accident.

As expected, Shell's second-quarter dividend was maintained at 42 cents a share.

The Anglo-Dutch company wants to sell a total of $7bn-$8bn of assets in 2010 and 2011 to help it focus on more attractive areas, an acceleration from the $4bn of disposals it would usually have targeted over two years.