Chevron Corp. "takes full responsibility" for the oil spill off Brazil, the U.S.-based supermajor's top executive in the South American country, George Buck, said.

The spill occurred earlier this month at a Chevron-operated appraisal well in the vicinity of the company's offshore Frade field, located 370 kilometers (230 miles) off the coast of Rio de Janeiro state at a depth of approximately 1,200 meters (3,930 feet) in the Campos basin, Brazil's main oil-producing area.

"The sheen, estimated at approximately 18 barrels or less in volume, is located about 120 kilometers (75 miles) offshore Brazil and continues moving away from the coast," Chevron said in a statement released on Sunday.

Between 200 barrels per day (bpd) and 330 bpd of crude spilled into the ocean from Nov. 8 to Nov. 15, but the flow has slowed in the past few days because the company capped the well, Brazil's National Petroleum Agency, or ANP, said.

"We are committed to deploying resources until the sheen can no longer be detected," Buck said.

Over the weekend, the head of the Brazilian Federal Police's environmental crimes unit, Fabio Scilar, questioned the legality and methods being used by Chevron Corp. to clean up the oil spill along the Atlantic coast.

The San Ramon, California-based company is "pushing" the oil to the bottom of the sea with high-pressure streams of sand, committing an environmental crime by polluting the ocean and endangering coral reefs, Scilar told Brazilian media Saturday.

The Federal Police has informally asked the oil company to change its clean-up strategy, Scilar said.

The company is working with Brazilian government agencies to "contain, reduce and eliminate the remaining oil sheen in the vicinity of its Frade field," Chevron said.

"Up to 18 vessels have been in rotating operation to support well plugging operations and sheen cleanup. The vessels are using oil response methods approved by the Brazilian government, such as deployment of containment booms and surface skimming. At no time has sand or chemical dispersants been used in the process," Chevron said.

Chevron Brasil Upstream Frade Ltda., which has a 51.7 percent stake, is the lead operator in the Frade field.

Brazilian state oil giant Petrobras has a 30 percent interest in the project and the Frade Japao Petroleo Ltda. consortium controls the remaining stake.

"Our emergency response teams are trained and prepared to address a potential spill incident," Buck said. "The moment the seeps were first identified, we immediately activated our emergency response plan and began dispatching necessary resources to safely manage the situation. We moved quickly to begin plugging and cementing procedures to seal the source. Our combined efforts greatly diminished the size of the sheen and stopped the source of the seep flow within only four days of first detection. We believe no new oil is seeping from the reservoir. Seep lines continue to drain in the form of droplets."

The company said it was analyzing data to determine how much oil was released into the ocean.

"This analysis is expected to be complete within days. Brazil's National Petroleum Agency (ANP) had estimated the total volume of oil released at approximately 5,000 to 8,000 barrels," Chevron said.

"A complete investigation is underway to understand the cause of the incident. Findings will be shared with Brazilian government agencies and Chevron's global operations to prevent this from happening again," the company said, adding that development drilling operations had been suspended in the field.