The oil is accumulated in Upper Miocene sandstone, trapped in Seria Anticline that straddles the present day coastline.

The finding of natural gas and oil not only improved the country's politics, finances, and culture, but it also altered the 1959 Constitution, ending the Resident System and paving the way for Brunei's independence from Britain.

[3] The exploration of the field started in late 1926, when F. F. Marriot (British Malay Petroleum Company Field Superintendent) and Thomas George Frederick Cochrane (General Manager of Sarawak Oilfields Limited) smelled "oil" (H2S) in the Kuala Belait and asked Straub, a Swiss geophysicist, to do a geophysical analysis of the area.

On 5 April 1929, oil began to flow from the S-1 well, marking a watershed point in Brunei's economic history.

[13] On 8 October 2004, Brunei Shell Petroleum made a new discovery in Seria North Flank which was an undrilled part of the oil field.