I've noticed the same things.
For the past two years, it has been rewarding to compare the development of the Sanish oil field ("owned" by Whiting) and the Parshall oil field ("owned" by EOG). Generally, there has been about seven rigs in the Sanish, and only one rig in the Parshall.
It appears that (and I've blogged about this often):
- Whiting was using the Sanish as a cash cow to cover costs elsewhere
- EOG was early to "hold by production" the entire Parshall, and then moved to explore the Eagle Ford
- now with the Eagle Ford development underway, and new completion techniques in the Bakken resutling in 100% return rate, EOG is ramping up in the Parshall
- telegraphed in EOG's 3Q13 earnings call
- five rigs in the Sanish
- six rigs in the Parshall (the six rig is right on the edge, and drilling into the Van Hook)
See more at EOG.