No injuries from Motiva Convent steam explosion -sources

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HOUSTON, Sept 28 (Reuters) - No injuries were reported from a Sept. 18 explosion during repairs to the fire-damaged heavy oil hydrocracking unit at Motiva Enterprises' 235,000 barrel per day (bpd) Convent, Louisiana refinery, sources familiar with plant operations said on Monday.

Workers were steaming out the drum on the idled 45,000 bpd hydrocracker, called the H-Oil Unit, said the sources, who requested anonymity because they were not authorized to discuss the matter with the media.

Outlets on the drum were left open but one or some of them became clogged causing steam pressure to build up in the vessel, which ruptured along a seam in the explosion, they added.

"The Motiva Convent refinery experienced a steam overpressure event on Sept. 18, 2016," Motiva said in an emailed statement. "There were no injuries or impacts to the environment or plant operations."

The company did not identify the unit involved.

The H-Oil Unit was shut by an Aug. 11 fire that heavily damaged the two production streams, called trains, on the hydrocracker. Repairs to one production train are expected to be completed the end of the year, restoring about half the unit's capacity to production.

Repairs to the second production train are expected to take at most a year to complete, sources told Reuters on Monday.

Steaming of the drum is a rarely performed procedure on the H-Oil Unit, the sources said.

Damage from the Sept. 18 steam explosion is expected to add a week to the repairs needed to return the unit to partial production by year end, the sources said.

The Convent refinery along with Motiva's refinery in Norco, Louisiana are to become part of Shell Oil Co, the U.S. arm of Royal Dutch Shell Plc (LSE: 0LN9.L - news) on April 1, Motiva has said.

Motiva's co-owners, Shell (LSE: RDSB.L - news) and Saudi Aramco (IPO-ARMO.SE), announced in March that they would divide their refining and distribution assets as they end their refining and marketing partnership. (Reporting by Erwin Seba; Editing by Richard Chang)