June 2, 2012. Chesapeake Energy Corp. said it drilled the largest oil gusher in the company’s 23-year history at a “significant” discovery in the Anadarko Basin of Texas and Oklahoma. The Thurman Horn 406H well in the Hogshooter formation produced 5,400 barrels of crude a day during its first eight days of operation, Chesapeake said. The output was more than twice that of some of the best performing wells in the Eagle Ford shale of south Texas, which Chesapeake counts as its most valuable holding. The discovery will accelerate the second-largest U.S. natural-gas supplier’s shift to more profitable crude production. Chesapeake shares have dropped 28 percent as gas prices hit a 10-year low and probes began of McClendon’s personal finances. Gas comprises more than 80 percent of the Oklahoma City-based company’s output. Chesapeake is seeking to sell $20.5 billion in assets by the end of 2013 to fill a cash-flow shortfall. The Hogshooter wells aren’t among the assets for sale.