State regulators say they’re cautiously optimistic that a major release of crude oil from a Chevron well in Kern County — an episode that has continued for three months — is finally over. Chevron told state officials Wednesday that more than 1.3 million gallons of oil and water have flowed to the surface in the Cymric oil field, 35 miles west of Bakersfield, since May 10. An estimated one-third of that, or 445,130 gallons, is believed to be crude petroleum. The spill, which Chevron and the state’s Division of Oil, Gas and Geothermal Resources describe as a “surface expression,” has led to a major cleanup operation near the town of McKittrick.