A leak in a pipeline that carries oil from U.S. Gulf of Mexico offshore facilities has halted production at two fields, Exxon Mobil Corp. and Royal Dutch Shell said April 13.

Shell said it temporarily halted production on its 100,000-barrel-per-day deepwater Perdido production hub April 9 after a subsurface leak was discovered on Exxon’s Hoover Offshore Oil Pipeline System (HOOPS). Production on Exxon’s Hoover platform also was halted because of the leak, Exxon said.

The HOOPS pipeline has been closed for repairs, a spokeswoman for Shell said.

Exxon has notified government agencies and shippers and has responded to an onshore release of crude oil at a facility in Freeport, Texas, spokesman Todd Spitler said April 13.

“We anticipate resuming flow on the line in a timely manner once it is safe to do so,” he said. Exxon did not say what caused the leak or how much production was affected.

HOOPS connects the Exxon-operated Hoover, Marshall and Madison offshore fields, which combined produce about 4,000 barrels of oil per day, according to a 2018 marketing brochure.

Shell’s Perdido hub is moored in some 8,000 feet (2,438 m) of water about 200 miles (322 km) south of Galveston and is a joint venture among Shell, BP Plc and Chevron Corp.

The 153-mile (246-km) HOOPS pipeline brings oil from several offshore oil fields to the Quintana Terminal near Freeport, according to an Exxon website.