But analysts said the reduction in drilling rigs in the United States could prove temporary as activity had been restrained by hurricane threats and as efficiencies improve.
"We think the fall in shale oil activity is an indication of rising costs, higher break-evens outside of geological sweet-spots, falling initial well productivity and cash-flow constraints at unsustainably low prices," Standard Chartered said in a note.
"However, the turn down in drilling has yet to temper the optimism of most forecasts of U.S. output growth in 2018."
Prices have been supported over the past few sessions by supply disruptions in northern Iraq, where tensions have been running high since the Kurdistan region's vote in favor of independence last month.
Crude oil exports through the Iraqi Kurdistan controlled-pipeline to the Turkish port of Ceyhan had risen to 288,000 bpd on Monday afternoon, from 255,000 bpd earlier in the day, a shipping source told Reuters. Typically, the pipeline transports about 600,000 bpd.
Security sources told Reuters that Iraqi forces were deploying tanks and artillery near a Kurdish-held area of northern Iraq where a section of the Kurdish oil export pipeline is located.
Iraqi Oil Minister Jabar al-Luaibi said on Saturday oil exports were increasing from the southern Basra region by 200,000 bpd to make up for a shortfall from the northern Kirkuk fields.