Reuters/Steve Sisney
- Shale industry legend Harold Hamm is looking to pull crude from "Generation 3" rock.
- This is a tougher form of rock that was largely neglected earlier in the shale revolution.
- Total US oil production recently hit an all-time high of 13.2 million barrels per day.
Shale industry legend Harold Hamm is looking ahead to the next potential breakthrough in US crude production.
A turn toward new practices would come as site depletion becomes a growing worry for the sector while rising costs mean drillers need higher crude prices to profit.