Prices have been range-bound for over 60 days on concerns of US output growth
While Opec reduced output for second month in Feb, US stockpiles have risen for 7 straight weeks
On Friday, the Brent May contract price settled at $56.31 a barrel
Rise in US inventories comes as members of the Opec and other producers have cut output
Oil prices inched higher, as investor optimism over the effectiveness of producer cuts
In the United States, rising output has helped push up crude and fuel stocks to record highs
Despite this, inventories remain bloated and supplies high, especially in the United States
Analysts say oil producers will have to cut production more quickly to drain global oversupply
US oil drillers over the past month have added the most drilling rigs since 2012
Sanctions news added to volatility in what had already been a day of choppy trading
Prompts investor concern about the Opec and other producers effectiveness at supporting prices by cutting supplies
Crude inventories rose 2.3 million barrels in the week to Jan 13
While the Opec signalled a drop in the global oil supply surplus this year
Gains were also capped due to rising US production
Global oil production remains high and inventories near record levels in many areas
OPEC agreed to cut output by 1.2 million bpd to 32.5 million bpd for the first six months of 2017
Brent crude futures was trading at $55.87 per barrel on Friday
Consumption of fuels, a proxy for oil demand, surged 10.7 percent to 196.48 million tonnes in 2016
Prices for Brent crude futures were trading at $53.77 per barrel at 0130 GMT
Prices for Brent crude futures were trading at $54.99 per barrel at 0136 GMT