London - Booming US shale output, which helped spark slumping oil prices, will continue over the next 20 years but start to slow, increasing demand for Opec crude, BP forecast Tuesday.
The British energy giant revealed its verdict in an annual global Energy Outlook report which covers the period 2013 to 2035.
"The current weakness in the oil market, which stems in large part from strong growth in tight oil production in the US, is likely to take several years to work through," BP said in the report.