HOUSTON, March 19 (Reuters) – Chevron was surprised when Exxon Mobil filed for arbitration over Chevron’s plans to buy Hess’s Guyana oilfield stake, Chevron CEO Michael Wirth said on Tuesday. The dispute threatens to derail Chevron’s $53 billion takeover of Hess. The 30% stake in the prolific Exxon-operated Stabroek oilfield in Guyana is Hess’s most valuable asset. Exxon says … Read more