Greenpeace members protest in front of the Chevron oil company headquarters in Rio de Janeiro in this November 18, 2011 file photograph. [Photo/Agencies]

RIO DE JANEIRO/NEW YORK - Chevron , the No.2 US oil company, said on Wednesday that oil from a new seabed seep at its Brazilian offshore field is chemically different to crude from a November spill, suggesting the two leaks are? unrelated.

An aerial view is seen of oil that seeped off the coast of Rio de Janeiro, caused by a well drilled by Chevron at Frade, on the water in Campos Basin in Rio de Janeiro state in this November 18, 2011 file photograph. Brazilian federal prosecutor Eduardo Santos de Oliveira filed criminal charges on Wednesday against Chevron and drill-rig operator Transocean for a November oil spill, raising the stakes in a legal saga that is adding to Chevron's woes in Latin America and threatens to slow Brazil's offshore oil boom. [Photo/Agencies]

Oil from a seep found this month 3 km (1.9 miles) from Chevron's November seafloor leak -- which spilled at least 2,400 barrels and triggered an $11 billion civil lawsuit and pending criminal charges -- is "much heavier" and has different chemical properties from crude in the earlier spill, Chevron told Reuters.

"There is no evidence that the two sets of seeps are related," Chevron spokesman Kurt Glaubitz said in an email to Reuters.

"Oil samples collected from the second seep and analyzed by the IPEX lab in Brazil and reviewed by Chevron indicate that the oil is not from the Frade production reservoir."

Chevron said oil from the recent seep contained no drilling "mud", suggesting it is not a residual spill or a new complication of the November spill. Only around 1 barrel of heavier crude has been found flowing out of the new seep.

As a precaution, Chevron has shut output at the 61,500-barrels-per day Frade field in Brazil, and will complete a new geological study of the Frade prospect with its partners there, including Brazil's state-controlled Petrobras. Chevron has spent more than $2 billion developing the field.

The Chevron statements come as executives from the company, and its drilling contractor Transocean are expected to face criminal charges on Wednesday for alleged environmental crimes related to the November spill.

That spill came after a pressure kick forced Chevron to shut in a new production well at Frade, which resulted in oil, gas and mud breaching its well beneath the seabed and eventually flowing out into the Atlantic Ocean. The spilled oil did not reach shore.

The discovery of a new seep in the Frade field this month has led to allegations by a Brazilian federal prosecutor that Chevron's drilling has led to dangerous faults in the undersea oil reservoir at Frade, which could be irreparably damaged and may eventually leak much more oil.

"That statement is not consistent with the facts," Glaubitz said.