Last month, LLOG Exploration, a US-based privately owned oil and gas company, initiated development studies for two hydrocarbon-bearing wells following a successful three-well exploration and appraisal campaign in the Gulf of Mexico, now rebranded as the Gulf of America.
This is according to a report by Offshore Energy.
The campaign, which included the Who Dat East and Who Dat South wells, has yielded promising results, prompting further evaluation of potential development options.
The Who Dat East well, drilled in late April 2024 using Noble’s Noble Valiant drillship, revealed a hydrocarbon-bearing aggregate net pay thickness of 44 m measured depth (MD), with 31 m MD within two discrete reservoir units.
The joint venture partners—LLOG (operator, 40%), Karoon (40%), and Westlawn (20%)—are now conducting development concept studies to assess the technical and commercial viability of the Who Dat East prospect.
Karoon has revised its net revenue interest (NRI) for Who Dat East’s 2C contingent resource upward by 190%, from 5.4 million barrels of oil equivalent (boe) to 15.7 million boe, based on data from wireline logs, fluid samples, and subsurface studies.
The Who Dat South well, drilled in the fourth quarter of 2024 using Seadrill’s West Neptune drillship, reached a total depth of 7,014 m MD.
Preliminary interpretations indicated hydrocarbon-bearing sandstone intervals with an aggregate true vertical thickness (TVT) of 67 m, exceeding pre-drill estimates of 40 m.
Initial analysis of formation pressure measurements and fluid samples confirmed the presence of high liquid yield gas-condensate fluid.
The well has been suspended as a potential future producer pending further joint venture studies.
In contrast, the Who Dat West well, drilled in late December 2024 and reaching a total depth of 7,147 m in January 2025, did not encounter significant hydrocarbon-bearing intervals and has since been plugged and abandoned.
Who Dat field production update
The Who Dat field, located in 800 m of water offshore Louisiana, has been in production since 2011. The field produces a mix of 60% oil and 40% gas from nine wells, processed through the Who Dat floating production system (FPS) and transported via common carrier pipelines.
Gross production in Q4 2024 averaged 29,576 boe per day, a 3% decline from the previous quarter due to an extended 18-day maintenance shutdown caused by Hurricane Rafael and a gradual 10-day ramp-up period to restore full production.
Average realised prices for Who Dat liquids, including oil, condensate, and natural gas liquids (NGLs), fell by 9% to US$68.44 per barrel, reflecting global oil price trends. However, the average realised gas price increased by US$83.07 per thousand cubic feet (mcf), driven by higher seasonal demand during winter.
Dr Julian Fowles, Karoon’s CEO and MD, said, “In the US, the Who Dat gross production for the quarter was 3% lower than in 3Q24, primarily due to the planned annual platform shutdown and gas compressor maintenance. As a mature asset, without interventions Who Dat production, is expected to naturally decline by approximately 15% pa on average.
“During 2024, natural decline was largely offset by well interventions, sidetracks and production system optimisations. 2025 production will also benefit later in the second half from two well interventions, in line with our long term aim to offset decline rates through periodic infield activities.”
