While shale gas has advanced to the point where environmentalist are making movies to try to stop it, tight oil production from similar shale reservoirs has flown under the radar so far. Yet is potential impact on US energy supplies may be far greater.
The graph at left shows how production has risen dramatically over the last decade from zero to almost 900,000 barrels a day, even though only two major reservoirs have been developed. The trend line splits the nine major fields by color coding. The Bakken – the cream-colored portion – has been by far the most productive, but the Eagle Ford in Texas is now starting to show results as well. The other seven fields have not yet entered full-scale production.
Most of the fields, but not all, are located on the map at the right. The Granite Wash is in western Oklahoma and Spring is in West Texas. The Monterey Shale, in central California, is believed to be the largest reservoir in North American, with four times the potential as the Bakken. (Why does California always get the best of everything?) The Woodford is not on this map but is beneath eastern Oklahoma, Texas and Arkansas. The Niobrara is at the juncture of Nebraska, Wyoming and Colorado. The Spraberry, also not shown, is in West Texas (which usually managed to be more productive than California). And the Austin Chalk, of course, is around Austin.
This vast potential of tight oil is the reason why the International Energy Agency and others are talking about the US achieving energy independence and even becoming an exporter by 2030. If the fields at the bottom of the graph begin to develop at anything like the rate of the Bakken and the Eagle Ford, the US is going to have a lot of oil.