Harbour Energy’s US arm advances repair plan after riser leak at Gulf of America oil & gas asset

July 24, 2026, by Melisa Cavcic

U.S.-headquartered LLOG Exploration, a subsidiary of Harbour Energy, has seen a drop in output at its asset in the Gulf of America (U.S. Gulf of Mexico) following a riser leak; however, the start-up of a sidetrack well is supporting near-term production, as the company and its joint venture (JV) partners move forward with a structured remediation plan to replace the riser.

After a minor riser leak was discovered at Who Dat in February 2026, approximately 15,000 barrels of oil equivalent per day (boepd) of gross production was affected from seven wells. The JV, comprising LLOG (operator, 40%), Karoon (40%), and Westlawn (20%), continues to progress a structured remediation plan, with the operator advising that the next phase involves removal and analysis of the riser, currently planned to kick off in the third quarter of 2026.

The E manifold production is expected to resume in 4Q 2027, subject to the results of this work. The operations to sidetrack the A1 production well began in early April with production starting on July 13. The output from the Who Dat A1 sidetrack continues to ramp up, currently producing 1,700 boepd NRI, in line with expectations.

Karoon explains that another sidetrack, G1 ST, is expected to be spud in 2H 2026, subject to final technical assessment and JV and regulatory approvals. If the go-ahead is given, this is expected to be a positive near-term production contribution while the JV continues to advance the E riser remediation.

Carri Lockhart, Karoon’s CEO and MD, commented: “At Who Dat, the A1 sidetrack came online on 13 July, providing a positive near -term contribution while the JV continues to advance the E riser restoration workstream. Operator LLOG is preparing to remove the riser that developed a minor leak for inspection and analysis, with removal operations expected to commence in the third quarter of 2026.

“Our current base case assumes one or both E risers will need replacement, with E manifold production expected to resume in the fourth quarter of 2027. The JV also continues to advance additional production opportunities across the asset.”

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The average realized price for Who Dat liquids, including oil, condensate, and NGLs, was $101.93/bbl, 55% higher than the previous quarter, in line with the increase in global oil prices and wider differentials for Mars – benchmarked crudes.

The Who Dat average realized gas price was $4.08 /mcf, down 47% from the previous quarter, reflecting the typical decrease in Henry Hub benchmark pricing during the U.S. Spring season, when natural gas power demand decreases.

The gross Who Dat production in 2Q 2026 was 1.03 million boe, compared to 1.67 million boe in 1Q 2026, at an average rate of 11,360 boepd, compared to 18,300 boepd in 1Q 2026.

Karoon elaborates that production for the quarter on an NRI basis was 0.2 4 million boe, compared to 0.38 million boe NRI in the prior quarter, reflecting the temporary shut-in of the E manifold.

Located in a water depth of 800 meters offshore Louisiana within federal waters of the U.S. Gulf, the Who Dat conventional deepwater oil and gas development came on stream in 2011.

The produced oil and gas are processed through the Who Dat floating production system (FPS) and transported to markets via common carrier pipelines.