The U.S. investment bank Goldman Sachs said on Monday that it expected oil price to be $50-$60 a barrel until 2020, due to improved shale oil productivity and higher supply from OPEC countries.

Earlier this month, the lender said that it expected Brent price to be $45 a barrel in 2016, up from an earlier forecast of $39, and WTI price of $45 per barrel in 2016, up from an earlier forecast of $38.

Goldman Sachs lowered its 2017 Brent price forecast to $55 a barrel, down from $60, and WTI price to $53, down from $58.