More than a year after exiting bankruptcy, SandRidge Energy Inc. is stuck in stock-market purgatory. The oil and gas explorer has seen its stock sink 37 percent since October 2016, despite a restructuring that wiped out $4 billion in debt. Activist investor Carl Icahn is threatening a proxy fight, and last week SandRidge rejected a merger that would have valued the once $11 billion company at just $589 million. For drillers trying to return from the fiscal brink, it’s a familiar plight. Even with global crude prices climbing, bankruptcy survivors such as SandRidge and Ultra Petroleum Corp. have found a second act’s not so easy. The companies have endured stock crashes, executive purges and shareholder revolts as investors learn the U.S. shale boom can’t save every player. SandRidge has fallen 33 percent […]