Block L covers an area of 2,253 sq. km. It lies in eastern onshore Brunei Darussalam, in the Brunei-Muara District and parts of Tutong and Temburong Districts. The block extends to the north approximately 5 km from the coastline to offshore while the eastern boundary covers most of Brunei Bay.

Historically, a few exploration wells had been drilled in the area where hydrocarbon indications were evident in the underlying reservoir. Block L also covers the Jerudong area, where a number of exploration wells were drilled, leading to the discovery of the Jerudong Oil field. More than 600,000 barrels of oil were produced from the field between 1955 and 1962. However, due to the attractiveness of prospecting offshore, some discoveries made using the technology at that time (1955 -1962) were left undeveloped and the whole of Block L area remains under-explored.

PetroleumBRUNEI and the Block L consortium signed the Production Sharing Agreement on 28 August 2006. The current consortium members are: AED South East Asia Limited (50%) – as the operator, Kulczyk Oil Brunei Limited (40%) and QAF Brunei Sdn Bhd (10%).