More oil-based drilling mud was found near ConocoPhillips's platform in Bohai Bay- a discovery that may push up the volume of the oil spill to a new high, the company said on Wednesday.

A man points to oil on the beach in Laoting county, Hebei province, on July 26. The oil is suspected to have come from the oilfield spill in Bohai Bay. [China Daily]

The Houston-based energy company estimated earlier that about 1,500 to 2,000 barrels of oil and oil-based drilling fluids had gone into the sea during the two leaks at Penglai oilfield.

"We anticipate that it will push the total amount of oil and oil-based drilling mud released to pass the previous estimate numbers." the company said in a statement on its website.

The State Oceanic Administration used remote satellites, patrol planes and boats to survey the oilfield from Wednesday to Sunday, identifying a polluted area of approximately 1,200 square km in the oilfield.

The North China Sea Branch of the SOA issued a notice on Monday ordering the company to appropriately dispose of contaminants to avoid further pollution from the oil spill, which started on June 4 near Platform B of the Penglai 19-3 oilfield.

Oil-drilling operations in the field are jointly conducted by COPC, a subsidiary of U.S. energy giant ConocoPhilips, and the China National Offshore Oil Corporation (CNOOC), the country's largest offshore oil producer.