Back in October, Jill Potts waved off concerns about falling crude prices, pointing to the long lines of trucks forming outside her oil field supply store in South Texas as evidence that the shale boom was still going strong. But then oil kept plunging — from $82.70 a barrel back on that sunny mid-October day to $70, then $60, and ultimately touching as low as $43.58 before settling at about $50 Thursday. Potts’s mood has changed. Standing inside her shop in Cuero, Texas, surrounded by industry wrenches the size of T-Rex femurs, […]