(Adds Motiva no comment in paragraph 4, background in paragraph7)
July 7 (Reuters) - Motiva Enterprises' 235,000-barrel-per-day refinery in Convent, Louisiana, plans tostart overhauling part of the heavy oil hydrocracking unit onMonday, according to sources familiar with the situation.
The entire 45,000-bpd hydrocracker, called the H-Oil Unit,is expected to be out of production for about two days while atower on the unit is isolated, the sources said.
If the isolation of the tower is successful, the remainderof the H-Oil Unit will return to production while the overhaulon the tower continues for about a month.
Motiva spokeswoman Destin Singleton said the company doesnot discuss specific details about maintenance activities at itsrefineries.
Performing the July overhaul will let Motiva postpone a fullshutdown of the H-Oil Unit from this fall until late in thefirst quarter or sometime in the second quarter of 2015, thesources said.
The refinery is weighing postponing a planned overhaul ofthe 92,000-bpd gasoline-producing fluidic catalytic crackingunit to 2018 from 2016, the sources said.
Motiva is a 50-50 joint venture between Royal Dutch ShellPlc and Saudi Aramco that operates threeU.S. refineries. (Reporting by Erwin Seba in; Houston; Editing by JeffreyBenkoe, Lisa Von Ahn and Jan Paschal)