oilprice.com:

The first three months of this year have made one thing crystal clear: Big Oil is set on expanding in shale―hardened by the lessons the oil price crisis taught it―and leveraging the experience of oil and gas independents.
 
Shale has lower production costs, at least in the U.S. and possibly in Argentina, and returns come sooner than those from conventional oil and gas projects. That combination is irresistible for Shell, Exxon, and Chevron, who have suffered to varying degrees from their traditional focus on big projects.
 

Go to link