Arjun Sreekumar says, "If the oil price falls below its marginal cost of production, drilling activity in costlier locations, such as Canada's oil sands and deepwater prospects offshore Brazil and Africa, could quickly become uneconomical. Mining projects in Alberta's oil sands, for instance, have breakeven costs in the $90-$100 per barrel range, according to consultancy Wood Mackenzie, leaving them especially vulnerable to lower prices."
Keith Schaefer writes, "The report says that massive infrastructure spending (pipelines, refineries, etc.) is a key to energy independence — and notes that oil companies have already proven unwilling to invest in new infrastructure at prices as high as $90 per barrel, despite most wells remaining profitable."
Marshall Kaplan says, "Many experts have indicated that the marginal cost of oil shale development is about $90 [per barrel]."
Dr. Sami Alnuaim writes, "The stability of the prices of OPEC basket during the last three years (2011, 2012, and 2013) to reach an average price of $106 a barrel despite of all the challenges and the many factors that could have negatively impacted the oil prices confirms this successful strategy...This high average oil price has also encouraged a lot of countries and oil companies to invest in exploration, development and production of what is so-called shale-oil..."