Hydraulic fracturing (frac)

Hydraulic fracturing pumps fluid, usually water mixed with sand and chemical additives, down a well at pressures high enough to crack open tight rock formations like shale. The sand props those cracks open once pumping stops, creating pathways for oil and gas that would otherwise be trapped in low-permeability rock to flow into the wellbore. Paired with horizontal drilling, it's the technology that unlocked shale plays across the country and reshaped U.S. production over the last two decades.

On the show, guests describe frac work as central to both new drilling and mature-field strategy — re-fracturing older wells to access reserves left behind by earlier completion techniques is increasingly common as easier inventory runs out, and academic researchers describe studying how fracturing behaves differently across rock types, from shale to the granite used in enhanced geothermal projects.