A Berman chart on ratio of debt to cash flow. 

Debt reduction thus far in 2021, the year of 'free' cash flow, is miniscule and some of the biggest of the big are still adding debt, not reducing it. Now the rhetoric is (as it should have been 9 months ago) if they're using cash flow to pay dividends and pretending to reduce debt, they can't drill enough wells to replace reserves and keep production, they'll have to start raising more money (to get deeper in debt) to drill more wells. Well, no shit. 

Shale oil is totally dependent on credit/debt; that's plain and simple.

I am convinced beyond a shadow of a doubt that if it were not for the internet, the US shale oil phenomena would have been over in 2015 when prices collapsed. It would have died a natural, no-profit death like every other unprofitable play in the world. It didn't because of  the amount of other people's money that was raised from that dog dookey the shale space says about itself, like rig efficiencies, paying down debt,
resilience and cash flow at the expense of reserve replacement.