Texas regulators are scrutinizing some of the biggest U.S. energy producers in the wake of several earthquakes that have rocked the Dallas-Fort Worth area. An Exxon Mobil Corp. XOM 0.07 % subsidiary and EOG Resources Inc., EOG 2.63 % one of the biggest shale-oil and gas pumpers, are facing questions about their use of injection wells to dispose of wastewater from hydraulic fracturing operations. The state’s oil-and-gas regulator on Wednesday begins a series of hearings in Austin to assess some oil companies’ role in causing the temblors. A growing body of scientific research from federal, state and academic researchers suggests that disposal wells, often used to get rid of the dirty water leftover from fracking and brine from oil-and-gas production, may be linked to increased seismic activity. Some in the energy industry are trying to discount those studies. The commission’s seismologist, Craig Pearson, has also expressed doubts that fracking […]