Brazilian oil regulator ANP approved Chevron Corp.'s plan to seal a leaking offshore well, the official Agencia Brasil news agency said Tuesday.

The leak began Nov. 8 at the well in the Frade field, located in the Campos Basin about 370 kilometers (230 miles) from the coast of Rio de Janeiro state.

The well lies at a depth of nearly 1,200 meters (3,934 feet).

Chevron's Brazilian subsidiary plans to begin by injecting mud into the well and then seal it with cement, according to Agencia Brasil.

The oil is leaking at a rate of 400-650 barrels per day, enough to create a stain of 163 sq. kilometers (63 sq. miles), though the patch of crude remains 120 kilometers (75 miles) from the coast, the news service said.

Eight Chevron ships and 10 vessels owned by other oil companies operating in the area have been assigned to containment and cleanup efforts.

Brazil's president, Dilma Rousseff, has ordered a "rigorous investigation" into the spill.

With a 51.7 stake, Chevron is the lead operator in the Frade field. Brazilian state oil giant Petrobras holds 30 percent of the venture and the rest belongs to the Frade Japao Petroleo Ltda. consortium.

Chevron, which began drilling in Frade in 2009, says the field contains 200 million to 300 million barrels of oil equivalent.