Brazil’s National Petroleum Agency says Chevron Corp has paid a multimillion dollar fine for several “irregularities” in connection with last year’s oil spill off the coast of Rio de Janeiro.

The agency says in a Thursday statement that Chevron paid the 35.1 million real ($17.3 million) fine last week for 24 of 25 irregularities detected. The statement did not provide details on the irregularities.

Some 155,000 gallons of crude are thought to have been released in the November 2011 spill.

The agency says it granted Chevron a 30 percent discount because it paid the fine on time and did not challenge it.

On Thursday, a federal court served Chevron and driller Transocean Ltd. with preliminary injunctions ordering them to suspend operations in Brazil .