America’s hottest oil patch is producing so much natural gas that by the end of last year producers were burning off more than enough of the fuel to meet residential demand across the whole of Texas. The phenomenon has probably only intensified since then.

Flaring is the controversial but common practice in which oil and gas drillers burn off gas that can’t be easily or efficiently captured and stored. It is lighting up the skies of West Texas and New Mexico as the Permian Basin goes through a massive production boom. Oil wells there produce gas as a byproduct, and...