Seria oil field
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. The exploration of the field started in late 1926, when F. F. Marriot (British Malay Petroleum Company Field Superintendent) and T. G. Cochrane (General Manager of Sarawak Oilfields Limited) smelled "oil" (H2S) in the  Kuala Belait area and asked Straub, a Swiss geophysicist, to do a geophysical analysis of the area. 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. On 8 October 2004, Brunei Shell Petroleum made a new discovery in Seria North Flank which was an undrilled part of the oil field. The well was drilled 3 km offshore in 8 metres of water by the Schlumberger self-propelled multi-purpose vessel. Wells. To date, more  than 900 wells have been drilled in Seria Field, and more than 350 wells are still in production. Key wells include: