Ramp-up of production at Pearl GTL has commenced and will continue into the summer, Shell, which co-owns the facility in a 50-50 joint venture with Qatar Petroleum, said in response to questions from a reporter.

The repair work was first reported by Reuters in a March 29 article based on statements by an unnamed official at Qatar Petroleum.

Pearl, which opened in late 2010, is the worlds largest GTL refinery, with capacity to produce 140,000 barrels per day of diesel and other hydrocarbon liquids and 120,000 b/d of natural gas liquids and ethane. The base oil plant has capacity to make 1.1 million t/y of Group III and 300,000 t/y of Group II.

Production by the overall facility began to flag in December when gasifier units that turn natural gas into liquid feedstock developed an unforeseen need for maintenance. On Feb. 1 operators halted operations altogether. Shell, the managing partner for Pearl, has not disclosed the exact cause of the problem with the gasifier units.

Industry sources have said that the loss of Pearls output was a significant factor, along with scheduled temporary maintenance shutdowns at other plants, in this years tightening of the Group III market. For much of the past few years, that segment had a large surplus that depressed prices. Prices rose in recent weeks as the surplus evaporated, but some say the surplus could return as Pearls base oil plant ramps up.

Shell has used most if not all of the Group III output to make its own finished lubricants. Without that supply, observers say the company tapped sources that had supplied other blenders.