ConocoPhillips’ Executive Vice President Alan Hirshberg used last Thursday’s 4Q2017 earnings conference call to highlight gains in the Permian Basin and the Eagle Ford and Bakken shales.

The three assets drove 70% of the Houston-based super independent’s 605 boe reserve additions last year, boosted by updated completion designs, Hirshberg said during the quarterly call.

“That, combined with getting more mature in the Lower 48 unconventionals, has given us more well history, allowing us to book additional reserves,” he said. “Our continuing lowering of unit costs also takes us out further in time with the economic life of these wells, allowing us to book a little more, so these increased bookings in the Lower 48 are really what allowed us to do that.”

Production costs are expected to remain flat, he said. There are inflationary pressures from oilfield services, but “continued, improved efficiency” offset the cost increases. “Our operating teams have demonstrated the ability to do that,” he said.

ConocoPhillips expects to average 100%-plus reserve additions annually over the next five years.

The current reserves potential is in the 10-11 years, “a reasonable place to be, but it is not something we’re aiming for one way or another,” he said. ConocoPhillips at this point is not trying to manage its reserves number up or down.