That was the lowest close for Brent since November 29, the day before OPEC agreed to cut output.
US rig counts due later in the day on Friday could add further downward pressure.
Additionally, the International Energy Agency (IEA) said that the non-OPEC nations like Canada, Brazil and the U.S. will add about 1.5 million barrels of supply in 2018, which is higher than the expected demand growth of 1.4 million barrels. USA crude futures CLc1, meanwhile, were down 3.4 percent to $44.92 a barrel, the lowest intraday level since May 5.
USA oil producers have added more than 400 extra rigs since the end of May 2016 in response to higher oil prices.
It said the International Energy Agency has recently published a forecast, stating that the global refinery is expected to go up by 2.7 million barrels per day (bpd) between July and August with refineries processing nearly 82 million bpd for the same period.
Then on Wednesday, the International Energy Agency said in a report that output growth among non-OPEC members such as the USA would outpace the increase in demand.
G7 meeting on environment confirms split on climate between United States , allies
As a result, the US said it would not join those sections of the communique on climate and multilateral development banks. Iowa City and Johnson County have united with other local governments nationwide to continue climate-change action.
"Should OPEC solve the problem of the overhang this year, it is just going to come back next year, so in any case their options are quite limited", said Mr. Weinberg.
The US Government's Energy Information Administration has forecasted domestic output growth to 460,000bpd this year revising the earlier prediction of a decline of 80,000bpd in December. The International Energy Agency is predicting an even larger increase.
"I think there's evidence that we're starting to see reactions by shale producers", said U.S. Bank Wealth Management's Haworth, "New investments are slowing down". Prices slid $1.72, or 3.5 percent, to $47 Wednesday.
On Friday, the oil prices have been edged up from lows of year 2017 but a current supply surplus has put them on path for their fourth consecutive week of losses.
But most producers have only hedged a relatively low proportion of output for 2018 so far, and the patience of private equity investors will not last forever.
Oil headed for the longest run of weekly losses since August 2015 as OPEC member Libya restored production just as the surplus in the USA showed few signs of abating.
Oil held losses below $45 a barrel after sliding to the lowest in seven months as US gasoline supplies unexpectedly rose for a second week.