Hundreds of small, independent producers might soon be swallowed up by today’s unprecedented oil and gas boom in southeastern New Mexico. As industry titans like ExxonMobil and Concho Resources pump billions of dollars into previously untapped sections of New Mexico’s century-old oil patch, the state’s small- and medium-sized producers are struggling on the margins to keep running aging wells based on outdated technology. Those companies, which have flourished for decades in New Mexico’s side of the Permian Basin, don’t have the resources to invest in the modern drilling technology needed to dig into the oil-rich, hard shale-rock formations where the...