Exxonmobil: "West Texas’ Permian basin has plummeted from $25 a barrel two years ago to $8 a barrel last quarter. Jeff Woodbury, Exxon’s vice president of investor relations"
Chevron: "has been able to cut development costs in the Permian from almost $20 a barrel last year to about $10 in the second quarter of 2016."
Source: http://fuelfix.com/blog/2016/07/29/energy-companies-finding-at-least-one-benefit-from-dowturn/