Chevron Corp. will restart a process unit at its Kapolei refinery in the coming week, ending a shutdown that began Dec. 19.

"We’re scheduling with our customers and we’re going to resume pretty much full operation," Chevron spokesman Albert Chee said. "We continue to update not only our state energy office but our customers. Right now everything is moving along smoothly."

The unit, which produces propane, was shut for mechanical issues. The refinery supplies local gas stations with motor fuel and the local utility with fuel oil.

The 54,000 barrel-a-day plant is one of two refineries in Hawaii, which derives almost 90 percent of its energy from petroleum, according to the U.S. Energy Information Administration. Tesoro Corp. also operates a refinery in Kapolei that can process up to 94,000 barrels a day.