This is from an otherwise very good SPE paper dated 2019, I think, discussing DCA methodology. When you do an actual DCA in the accelerated life span of a tight oil or gas well can make a 35% difference in realized EURs. Put another way, if you do the DCA at month 4 it's going to be much higher than doing it at month 24, even when adding realized production to the EUR estimate.

This graphic above was made before "downsizing," a shaleism for drilling wells closer together. So, I no longer believe the chart is very realistic. Neither would Novi, who suggests that up to a 60% degradation is occurring in over 50% of the remaining Tier 1 and 2 drillable locations in the Midland Basin. That degradation (or pressure depletion) is reducing well productivity and ultimate EURs pretty significantly. And quickly. If you discount the cash flow stream by 25%, per Novi, which I don't know why you would when you get most of your money back by year 3, a 30% degradation factor makes the well uneconomic. That's at prices over $70, below $58 they are all "uneconomic."

Operational methodology would change this scenario as well. For instance, rate of withdrawal for cash flow purposes. Preservation of BHP is a thing of the past; they now yank on them very hard, from the get-go. So hard, in fact, they make frac sand back by the truck loads.

So, I am inclined to believe that 50% of a typical Permian Basin HZ well's EUR is recovered sooner than 3 years and, because rates of decline have increased with longer laterals...80-90% of the EUR is realized much sooner than 15 years. Like maybe 10-12 years, but that is off the cuff. Today's Permian wells won't make it to year 20; they reach economic limits around year 15 at prices below $75, for instance. And the more water they are going to produce, which you can count on, the higher the OPEX will be to operate wells below 20-25 BOPD and the sooner economic limits are reached. You can also count on that.

On rates vs. cumulative oil, or cumulative gas charts I've been showing you lately for lateral lengths you can definitely see this earlier percentage of EUR recovery in play.