Oil output in North Dakota, which produced 910,000 bpd in August fueled by shale, still has room to expand, Continental Resources chief executive Harold Hamm told the Bloomberg Oil & Gas Conference.

"We still see the technology developing. Completions are better," Hamm said, reckoning the industry has made it "75%" of the way to optimising the prospect.

"We’ve climbed the learning curve a long ways."

Continental