Hydraulic-fracking drillers find more sand means more oil Somewhere amid the maze of wells that Murphy Oil Corp. has scattered across Texas’s sprawling Eagle Ford shale formation, Brett Pennington is carrying out a little experiment. What will happen, the exploration chief wants to know, when he jams huge quantities of sand down the narrow mouth of one of these wells. Will more crude seep out? Or, rather, will he smother the opening and choke off the flow? For the experiment, he’s amped up the sand meter all the way to 3,000 pounds per foot, almost double the average that each well in the Eagle Ford gets nowadays. If Pennington’s project seems a bit extreme, it also serves to underscore a trend spreading rapidly across a shale industry that’s scrambling to remain profitable after oil prices sank […]