Chesapeake Energy Corp.’s bonds have plunged to half their face value as lenders fret that tumbling energy prices are hurting their chances of getting paid on borrowings that are three times the current worth of the company’s oil and gas fields. The producer’s $1.5 billion of 4.875 percent notes due in April 2022 dropped 9.625 cents this week to 50.375 cents on the dollar, according to Trace, the bond-price reporting system of the Financial Industry Regulatory Authority. The Oklahoma City-based company estimates the discounted value of its proven oil-and-gas reserves will fall to about $4.2 billion by the end of the year down from $22 billion last December. Chesapeake shares have been the worst performer among their peers in the Standard & Poor’s 500 Index this year, plunging 73 percent. The downturn in oil markets has been especially painful for the driller because it happened just as the company […]