We estimate that a dual-fuel shale rig, running on in-basin natural gas would save $2,300/day (or c$30k/well), compared to a typical diesel rig. This is after a >20% IRR on the rig’s upgrade costs. The economics make sense. However, converting the entire Permian rig count to run on gas would only absorb c100mmcfd: not much of a dent in c1bcfd of flaring, as 2020 gas bottlenecks bite. This model shows all our workings.