On August 28, 2006, PetroleumBRUNEI signed the Production Sharing Agreement with Loon Brunei Limited (Loon) and QAF Brunei Sdn Bhd (QAF). In December 2006, PetroleumBRUNEI approved the assignment of 50% working interest and operatorship in Block L to Nations Petroleum. Loon and QAF hold 40% and 10% interests respectively.

Most of the 2,253 sq. km. of Block L 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 attraction 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.

 A 350 sq. km. 3D seismic programme is currently being carried out over the most prospective targets in Tutong district in order to determine the best sites for exploration wells. This is the largest 3-D seismic survey ever carried out onshore Brunei Darussalam. The consortium has committed to drill two exploration wells during the first phase of the exploration period.