(Adds Shell statement, paragraphs 5-7)
HOUSTON, Jan 28 (Reuters) - Motiva Enterprises isrepairing piping on a 95,000 barrel per day (bpd) coking unit atits 600,250 bpd Port Arthur, Texas, refinery, where productionhas been reduced due to planned work on other units, sourcesfamiliar with plant operations said on Wednesday.
The coking unit, called Delayed Coking Unit 2, increases theamount of refinable material from a barrel of oil and convertsresidual crude into petroleum coke, a coal substitute.
The coker was shut last week and is expected to be out ofproduction for a total of four weeks, said the sources, whodeclined to be identified because the information is not public.
Production at the Port Arthur refinery has been reducedwhile the 92,000 bpd gasoline-producing fluidic catalyticcracking unit (FCCU), 49,000 bpd reformer, 18,000 bpd alkylationunit, and a sulfur recovery unit are shut for planned work thatbegan on Jan. 12, according to the sources.
Motiva spokesman Ray Fisher said on Wednesday that Motivaroutinely plans maintenance on units at the refinery to ensurethey continue to operate safely and reliably.
"We schedule our maintenance programs in advance," Fishersaid. "We have begun maintenance activities at the Motiva PortArthur Refinery."
He declined say which units were undergoing maintenance orwhen the work is scheduled to finish.
Crude intake at the refinery is down at least 100,000 bpdwhile the work is underway. The refinery's largest crudedistillation unit, the 325,000-bpd-capcity Pipestill 5, istaking in about 200,000 bpd of crude during the overhaul.
The FCCU is expected to be shut for a period lasting atleast seven weeks that began on Jan. 12. The other units arealso being worked on during the same period.
Motiva's Port Arthur refinery is the largest in the UnitedStates. Motiva is a 50-50 joint-venture between Royal DutchShell Plc and Saudi Aramco (Reporting by Erwin Seba; Editing by Meredith Mazzilli, RichardChang and Peter Galloway)