Subsea7 wins $50–$150 million contract from LLOG Exploration for Who Dat East development in the US Gulf of Mexico

Subsea7 has landed a contract worth between $50 million and $150 million from LLOG Exploration Company LLC, a subsidiary of Harbour Energy, to develop the Who Dat East project in the US Gulf of Mexico. The work centers on a deepwater site sitting roughly 4,265 feet below the surface in lease MC 509-1.

Contract award and project location

Subsea7 has picked up what it classifies as a “sizeable” contract — somewhere between $50 million and $150 million — from LLOG Exploration Company LLC, a subsidiary of Harbour Energy. The project is the Who Dat East development, located in the US Gulf of Mexico at lease block MC 509-1.

The site sits at around 4,265 feet of water depth — firmly deepwater territory. That kind of depth demands specialized equipment and serious engineering expertise, areas where Subsea7 has built its reputation across years of offshore work in multiple global basins.

The original Who Dat floating production system is an established fixture in the Gulf of Mexico, and this new development extends its reach into adjacent acreage.

Who Dat East is an expansion of an already-operating asset. The original Who Dat floating production system is an established fixture in the Gulf of Mexico, and this new development extends its reach into adjacent acreage. For LLOG, it’s a way to pull more value from a region where the company has been active for years.

Scope of work and technical specifications

The contract covers a technically demanding set of deliverables. Subsea7’s scope includes fabrication, transportation, and installation of an 18-mile steel catenary riser and pipe-in-pipe system — infrastructure that ties directly back to the existing Who Dat floating production system, connecting the new East development to an already-operational hub.

Steel catenary risers are a standard deepwater Gulf of Mexico solution, built to handle the dynamic loads and pressures that come with operating at significant water depths. The pipe-in-pipe configuration adds thermal insulation, helping keep produced fluids flowing efficiently from the seafloor to the surface facility.

Umbilical and subsea controls installation is also part of the scope. These systems let operators run subsea equipment remotely, manage flow control, and monitor seabed conditions — essentially the nerve system connecting the seafloor infrastructure to the floating production facility above.

Project management and engineering kick off immediately, based out of Subsea7’s Houston, Texas office. Houston puts the project team close to the client, the supply chain, and the regulatory environment governing offshore work in US waters — a natural home base for Gulf of Mexico operations.

Timeline and offshore activities

Work on Who Dat East is already underway in a planning and engineering capacity. Subsea7 confirmed that project management and engineering activities begin immediately following the contract award — front-end work that’s essential before any vessel reaches the field, given how much preparation deepwater installation campaigns require.

Offshore installation is expected to begin in 2028. That timeline reflects the complexity involved: engineering, procurement, fabrication, and logistics all need careful sequencing before heavy-lift and installation vessels can mobilize to the site. Houston will serve as the operational hub throughout, keeping communication flowing between Subsea7’s technical teams and LLOG’s project stakeholders.

Background: Subsea7 and LLOG’s existing relationship

This contract didn’t come out of nowhere. Subsea7 has pointed explicitly to a longstanding relationship with LLOG Exploration as part of the context for this award. Craig Broussard, Senior Vice President for Subsea7 US, said the company is “proud of our longstanding relationship with LLOG, and our shared commitment to creating greater value from their US developments.”

That language signals more than a routine vendor relationship — it suggests the two companies have worked together across multiple Gulf of Mexico projects, building enough familiarity and trust to make continued collaboration a natural outcome. LLOG is a significant player in the US Gulf, and as a subsidiary of Harbour Energy, it brings both financial backing and operational focus to its regional developments.

Broussard also noted that Subsea7 looks forward to “supporting LLOG’s ongoing success across the region,” hinting that this contract may not be the last chapter in the relationship. Winning work from an established partner in a high-value basin is a meaningful addition to Subsea7’s US backlog.

A contract valued between $50 million and $150 million

Here’s what’s been announced: Subsea7 has secured a contract valued between $50 million and $150 million from LLOG Exploration Company LLC, a Harbour Energy subsidiary, for the Who Dat East development in the US Gulf of Mexico. The project sits at roughly 4,265 feet of water depth at lease MC 509-1.

The scope covers an 18-mile steel catenary riser and pipe-in-pipe system, plus umbilical and subsea controls installation, all tying back to the existing Who Dat floating production system. Engineering work has already started at Subsea7’s Houston office, with offshore activities scheduled to begin in 2028. The award reflects an ongoing working relationship between the two companies in the Gulf of Mexico.

Kelly Lippke

Kelly is an experienced writer with 15 years of experience exploring the big stories that shape our world, from tech breakthroughs and space exploration to climate, energy, and the fascinating quirks of science. She has a talent for turning complex ideas into sharp, memorable insights that stay with readers long after they’ve finished reading.