BEIJING, July 24 - Oil headed for weekly gains on Friday, as Houthi attacks on tankers in the Red Sea sparked worries about the closure of a second shipping chokepoint, while Kazakhstan temporarily cut output after its main export route was forced to shut.
Brent futures eased ¢72, or 0.72 per cent, to US$99.97 a barrel as of 0126 GMT, but remained on course for a 13.5 per cent advance this week. West Texas Intermediate futures fell ¢70, or 0.76 per cent, to US$91.49 a barrel, on track for a 10.9 per cent weekly rise.
Brent had settled up seven per cent and WTI up 6.2 per cent on Thursday, the first time since May that Brent settled above US$100 after Iran-aligned Houthis said they had struck two Saudi oil tankers in the Red Sea.
Prices were driven up by fears that the attacks would lead to the closure of the Bab el-Mandeb shipping route, which controls access from the Red Sea to the Indian Ocean and is the second most important oil channel after the Strait of Hormuz.
United States (US) President Donald Trump vowed to "hold Iran responsible" for any further attacks.
On Monday, the Iran-aligned Houthis declared that they were imposing a naval blockade on Saudi Arabia, which had been diverting its oil via pipeline to get around Iran's closure of the Strait of Hormuz.
Tehran had been pressing the Houthis to close the Bab el-Mandeb gateway to the Red Sea if the US continued to attack Iranian power infrastructure, after an interim truce between the two countries collapsed two weeks ago.
"The noose around global energy supply routes is pulling tighter again," IG market analyst Tony Sycamore said in a note.
Also on Thursday, Kazakhstan's Energy Ministry said oil companies temporarily cut back production after suspected Ukrainian drone attacks forced the country's main Black Sea export terminal to close.
On Tuesday, industry sources said that the Caspian Pipeline Consortium stopped receiving oil from Kazakhstan after suspending loadings because of attacks on tankers at the terminal. The route handles about two per cent of global daily crude supply.
The Energy Ministry did not specify the scale of the production reductions, but one source said Kazakhstan's biggest field had cut output by more than half.
