The Brazilian government filed charges against Chevron and Transocean for the March seep and for the spill of more than 2,500 barrels of oil at the Frade field in November. Chevron said the incidents aren't related.
The Brazilian government issued a court order that would suspend operations for Transocean and others working in Brazilian waters within 30 days while both spills are under investigation.
Guy Cantwell, a spokesman for Transocean, said the Brazilian case doesn't hold merit.
"We reiterate that Transocean crews acted responsibly and quickly, following the highest industry standards," he told Bloomberg News. "We have a very strong case and we will use every legal means necessary to prove it."
An estimated 50 billion barrels of oil are through to be off the Brazilian coast.
Transocean said it would continue working in Brazil as it studies the court order.
Chevron shut down operations at the field after the March incident.