HOUSTON (Reuters) - Royal Dutch Shell Plc (RDSa.L) halted the restart of the heavy oil hydrocracking unit (HCU) at its 235,000 barrel per day (bpd) Convent, Louisiana, refinery on Tuesday due to a leak, sources familiar with plant operations said.
A Shell spokesman said operations were stable on Tuesday at the Convent refinery.
The refinery began restarting the 45,000 bpd hydrocracker, called the H-Oil Unit, over the weekend. Shell was planning to return the unit to operation by the end of this week.
Shell became the sole owner of the Convent refinery on Monday when it and previous refinery co-owner Saudi Aramco divided the assets of their Motiva Enterprises LLC [MOTIV.UL]joint-venture.
Refinery officials decided last week to shelve plans to keep the H-Oil Unit shut for three months to repair cracks in welds seen in X-ray photographs, sources told Reuters. The officials concluded the X-rays had been misread.
The H-Oil unit, which produces motor fuels, primarily diesel, from residual crude oil, has not run at full capacity since an Aug. 11, 2016 fire severely damaged the unit.
The unit has been running at half capacity since late November 2016, following repairs. It was shut on March 3, 2017 ahead of a planned restart at full capacity. A fire broke out on the unit on March 18, 2017 requiring three weeks of repairs.
As the repairs neared completion in early April of this year, the officials decided to delay the unit’s restart to repair piping in the main production sections. The repairs were expected to last into July.
The Convent refinery's H-Oil unit is unique because it converts residual crude under high heat and pressure in the presence of hydrogen and a catalyst into motor fuel.
Most refineries send their residual crude to a coking unit to produce motor fuel feedstock and make petroleum coke, a coal substitute.
Reporting by Erwin Seba; Editing by Bernard Orr