Seria Oil Field also known as Seria Field is the largest oil field in northwest Borneo, discovered in 1929. The oil is accumulated in Upper Miocene sandstone, trapped in Seria Anticline that straddles the present day coastline. This field has produced more than 1 billion barrels of oil for more than 75 years. Brunei Shell Petroleum (BSP) is the operator of this field. At the end of World War II, the Japanese ignited 14 of the 21 wells in the Seria field before evacuating. Australian servicemen attempted to control the fires by stopping the flow of the wells.