Futures were little changed in New York following Friday's 1.8 percent advance. U.S. explorers added two rigs last week to 722, the highest level since April 2015, Baker Hughes Inc. said Friday. After the market was unimpressed with the accord Thursday to prolong output curbs, Saudi Arabia's Energy Minister Khalid Al-Falih said the strategy is working and global stockpiles will drop faster in the third quarter, Bloomberg wrote.

"We will see oil production tightening from the third quarter and it's highly likely that prices will rebound," Hong Sung Ki, a commodities analyst at Samsung Futures Inc., said by phone in Seoul. "What's concerning is what happens after the nine-month agreement because there isn't an exit plan, while U.S. producers will probably boost output at least until the second half of this year."

Oil in New York clawed back from its tumble toward $45 in the run up to the meeting in Vienna as Saudi Arabia and Russia rallied support for the deal. Meanwhile, U.S. inventories dropped seven weeks in a row, though they still remain above the five-year average and production rose to the highest since August 2015.

Read alsoBloomberg: OPEC, allies to extend oil cuts for nine months to end glutWest Texas Intermediate for July delivery traded at $49.64 a barrel on the New York Mercantile Exchange, down 16 cents, at 1:17 p.m. in Seoul. Total volume traded was about 15 percent below the 100-day average. Prices rose 90 cents to close at $49.80 on Friday.

Brent for July settlement was at $52.03 a barrel on the London-based ICE Futures Europe exchange, down 12 cents. The contract gained 69 cents, or 1.3 percent, to settle at $52.15 on Friday. The global benchmark crude traded at a premium of $2.37 to WTI.

Rigs targeting crude in the U.S. increased for a 19th straight week in the longest streak of gains since August 2011, according to Baker Hughes data. While the number of working rigs has more than doubled from last year's low of 316, it was the smallest increase this year. Drillers in the D-J/Niobrara Basin in Colorado led the growth last week, adding 4 for a total of 27 oil rigs in the region.