The FTSE 100 ended the week on the up, closing 1.28% ahead at 6,789.74.
John Wood Group, the oil services business, finished the day at the top of the blue chip risers, with its share price up 4.42% at 628p.
A production cut by OPEC and its allies sent oil companies to the top of both indexes.
On the FTSE 250, Premier Oil's share price rose 14.75% to 75.85, followed by Tullow Oil, up 7.4% at 189.6p and Cairn Energy, ahead 4.8% at 167.7p.
An earlier statement by Primark that it had experienced a "challenging November" meant that its parent company, Associated British Foods, was the biggest faller on the FTSE 100.
Its share price fell 4.6% at £22.42.
The FTSE 250 ended 0.51% higher at 0.51% at 17,844.11.