Traders said speculators continue to bet on further upside, expecting potential supply disruptions and further drawdowns, driven by strong demand.
Flooding from tropical storm Harvey caused ongoing large-scale US refinery outages on Tuesday, while crude prices rose on the back of supply disruptions in Colombia and Libya.
Oil prices held just below eight-week highs on Thursday, supported by a steeper-than-expected decline in US crude inventories that boosted expectations of a shift to a more balanced market.
Oil prices fell on Wednesday after a rise in US crude inventories and ongoing high output from Opec producers revived concerns of a fuel supply overhang.
Oil prices rose on Tuesday, supported by a weaker dollar, but crude continued to be weighed down by surging US production and uncertainty over whether an Opec-led supply cut is big enough to rebalance the market.
Oil prices fell on Monday, pulled down by rising US drilling activity and by doubts whether an Opec-led production cut initially due to end in mid-2017 would be extended.
Oil prices on Tuesday fell close to its lowest in a week as the market discounted the latest talk by Opec that it would extend output cuts beyond June.
Oil prices on Wednesday climbed for the first time in more than a week on a surprise drawdown in US crude inventories and data from the International Energy Agency (IEA) suggesting Opec cuts should create a crude deficit in the first half of 2017.