Oil Barrel

Oil Barrel is an drill fuel that grants  Drill Fuel to Drills when applied.

Obtaining
Oil Barrels can be obtained from treasure chests in the Crystal Hollows or as a reward from placing Crystals in the Crystal Nucleus.

Trivia

 * The Oil Barrel ' s description "100% unrenewable energy!" is a reference to the Biofuel's description "100% renewable energy"