Investors in Asian oil and gas companies should prepare for a wave of writedowns after a collapse in crude prices. CNOOC Ltd., Santos Ltd. and Inpex Corp. are among explorers and producers that may report full-year net losses because of writedowns that may be equal to as much as 10 percent of book value, analysts at Sanford C. Bernstein & Co. in Hong Kong wrote in a report Tuesday. “The future value of oil and gas properties has been significantly reduced,” according to the Bernstein analysts, including Neil Beveridge. “The impairment loss will likely be larger than earnings for the year for some companies, pushing several E&P’s in the region into a loss.” Oil prices have tumbled almost 70 percent in the past two years, weighing on earnings and forcing explorers to cut spending. Writedowns at Santos , the Adelaide-based energy company that built the $18.5 billion Gladstone liquefied […]