Combines Motiva urgents, adds storm impacts/non-impacts at other refineries in area, background on units

By Erwin Seba

HOUSTON, April 10 (Reuters) - The small crude distillation unit (CDU) and Base Oil Plant were shut on Wednesday at Motiva Enterprises MOTIV.UL 626,000 barrel-per-day (bpd) Port Arthur, Texas refinery, the nation's largest, said people familiar with plant operations.

No injuries were reported at four refineries in Port Arthur and Beaumont, Texas from a line of severe thunderstorms that also triggered a tornado warning, said people familiar with operations at the plants.

The 90,000-bpd VPS-2 CDU and Base Oil Plant were shut at Motiva after the line of thunderstorms swept through east Port Arthur on Wednesday morning, the sources said.

The Base Oil Plant produces 40,000 bpd of base oils used to make lubricating greases and oils.

Valero Energy Corp's VLO.N 335,000 bpd Port Arthur refinery, which is near the Motiva plant, saw superficial damage, but all units remained in operation, said people familiar with operations at Valero.

TotalEnergies TTEF.PA 238,000-bpd Port Arthur refinery, located near Groves, Texas, was restarting on Wednesday a diesel hydrotreater following a Tuesday malfunction.

TotalEnergies operations were unaffected by the storm, said people familiar with operations.

Also unaffected by the severe weather on Wednesday was Exxon Mobil Corp's XOM.N 619,024 barrel-per-day (bpd) Beaumont, Texas refinery, the U.S. second largest, said people familiar with operations at Exxon.

VPS-2 is the smallest of three CDUs breaking down crude oil into feedstocks for all other units at the Motiva refinery.

Diesel hydrotreaters use hydrogen to remove sulfur from diesel in compliance with U.S. environmental rules.

(Reporting by Erwin Seba; editing by Diane Craft)

((erwin.seba@thomsonreuters.com; +1 832 746 4269; Reuters Messaging: erwin.seba.thomsonreuters.com@reuters.net))