storage tanks are seen at marathon petroleums los angeles refinery which processes domestic  imported crude oil into california air resources board carb gasoline diesel fuel and other petroleum products in carson california us march 11 2022 reutersbing guan melbourne may 13 reuters  oil prices firmed in early trade on friday but were headed for their first weekly losses in three weeks as worries about inflation and chinas covid lockdowns slowing global growth outweighed concerns about dwindling fuel supply from russia brent crude futures were up 97 cents or 09 at 10842 a barrel at 0008 gmt while us west texas intermediate wti crude futures climbed 100 or 09 to 10713 a barrel both benchmark contracts were however on track to post declines for the week with brent set to drop more than 3 and wti more than 2 the market is continuing to be pushed and pulled by the prospect of a european union ban on russian oil sapping supply and concerns about demand being dented by weaker global growth inflation and chinas covid curbs the demand concern factors have grown quite a bit said commonwealth bank commodities analyst vivek dhar inflation and aggressive rate rises have driven the us dollar to 20year highs which has capped oil price gains because the strong dollar makes oil more expensive for buyers holding other currencies analysts however continue to focus on the prospect of a european union ban on russian oil after moscow imposed sanctions this week on european units of stateowned gazprom and after ukraine stopped a gas transit route oil is finding support from supply concerns as russia takes another step forward to weaponize energy said spi asset management managing partner stephen innes an international energy agency report on thursday highlighted the duelling factors in the market saying rising oil production in the middle east and the united states and a slowdown in demand growth are expected to fend off an acute supply deficit amid a worsening russian supply disruption read more the agency said it saw output from russia falling by nearly 3 million barrels per day bpd from july or about three times more than is currently displaced if sanctions for its war on ukraine are expanded or if they deter further buying