A drilling crew member on an oil rig in the Permian Basin near Wink, Texas.

Big oil is getting even bigger in shale, and that could speed up a shakeout among independents and force more mergers and joint ventures.

Last week, both Exxon Mobil and Chevron said they would boost their growth in the Permian basin substantially.

"All those companies [the majors] have demonstrated multi-decades history of delivering well on larger projects," said Nathan Strik, energy utilities sector leader at Fidelity.

Exxon expects to boost production to 1 million barrels a day in five years in the 75,000 square mile area that runs through West Texas and southeastern New Mexico. Chevron expects to more than double its output to 900,000 barrels a day in four years.

The contrast between those major producers, who can realize profits even when oil prices are low, and some others in the oil patch was a topic of discussion at the industry's annual IHS Markit CERAweek conference.