OTC 2025: Gulf operators make case for more subsea tiebacks

Bruce Beaubouef, Managing Editor

The US Gulf of Mexico is seeing a surge in subsea tiebacks due to their cost-effectiveness and shorter cycle time compared to standalone facilities.

The EIA has forecasted that there will be at least seven new tiebacks in the US Gulf in 2024-2025, which will support 12 new fields that will be brought online in that timeframe.

The opportunities and challenges of subsea tiebacks were the focus of several operating company officials at a panel discussion held on Tuesday at the Offshore Technology Conference in Houston.

Industry officials discussed ways in which they can increase their collaboration on subsea tiebacks at a panel discussion held on Tuesday at the Offshore Technology Conference in Houston.

At the subsea tiebacks panel, officials from LLOG Exploration Co, Talos Energy, Oxy, Shell, and Beacon Offshore Energy made the case that both producers and operators can benefit from working together on tying back new but smaller fields to existing platform infrastructure.

One example could be seen with Beacon Offshore Energy’s planned Zephyrus tieback in Mississippi Canyon block 759, which will be tied back to the Shell-operated West Boreas subsea infrastructure for further processing before moving onto the Shell-operated Olympus production platform.

Michael Clarke, Vice President, Deepwater Developments for Beacon Offshore Energy, said that his company was working with Shell to bring this field online in late 2025. Of the Beacon-Shell relationship, Clarke said that “we are very aligned with Shell in making the Zephyrus field a success.”

Clarke also noted that Beacon had worked with Occidental Petroleum Corp. (Oxy) to develop the Winterfell field in the Green Canyon area through a 13-mile subsea tieback to the Heidelberg spar platform in Green Canyon block 860. Working with Oxy, Beacon was able to bring this field online in July 2024.

Sam Fowler, Subsea Facilities Engineering Manager at Oxy, noted that his company had cooperated with producers on a number of tiebacks in the Gulf. Oxy has ten platforms in the Gulf, so there are plenty of opportunities for tiebacks to these structures, and Oxy has facilitated those relationships, Fowler noted.

In addition to the aforementioned Winterfell tieback to the Heidelberg spar, in recent years Oxy has also worked with LLOG on its Buckskin tieback to the Lucius spar; with Woodside on a tieback to the Marco Polo TLP; and with Beacon again on a tieback to its Marlin TLP. For its part, Fowler noted that Oxy is working to upgrade many of its Gulf platforms and extend their lives, so that they will be available to future tieback opportunities.

Glenn Mediamolle, Vice President-Offshore Development with LLOG Exploration, noted that his company had worked with third-party operators on its Taggart field, which ties back to Eni’s Devils Tower spar in Mississippi Canyon block 773, as well as the aforementioned tieback of its Buckskin field to the Lucius spar. Overall, he noted that LLOG had executed 30 tiebacks in the Gulf over the course of its field development efforts.

Talos Energy has also facilitated tiebacks to its platforms from other producers. “We welcome tiebacks from other companies to our production hosts,” said Joseph Sauvageau, Vice President—Asset Development with Talos Energy. He noted that LLOG had tied back its Praline field in Mississippi Canyon block 74 to the Talos Energy-operated Pompano platform in Viosca Knoll block 989 in 2021.

Sauvageau also noted that LLOG had tied back its Spruance discovery in Ewing Bank blocks 877/921 to Talos’ Lobster platform in Ewing Bank block 873. Talos became the operator of the Lobster platform in the wake of its February 2023 acquisition of EnVen Energy Corp.

Sada Iyer, General Manager Projects—Gulf of Mexico for Shell, echoed many of these same themes. “We bring in one to two tiebacks to our platforms per year, and many of these are tiebacks from third-party fields.”

Iyer conceded that Shell had evolved its thinking on allowing other producers to access its platforms over the past five years, noting that Shell recognized that it needed to keep its platform hubs operating at something close to nameplate capacity. To do that, it will need tiebacks from other producers. “We’re not [currently] running full on many of our assets. Therefore we will need more tiebacks. We want to invite others. We are open for business.”

Iyer also noted that technical factors will necessitate greater cooperation, particularly on subsea tiebacks. Recent and upcoming discoveries in the Gulf are producing more asphaltenes, he said, and the HP/HT reserves now being brought online are resulting in more scaling than has been seen in the past. “We all need to plan for these things,” Iyer said, including the ways in which topsides equipment will need to be modified to process these reserves.

“There needs to be an enhanced level of partnership on these types of projects, not only between operators of facilities and producers, but with suppliers as well,” Iyer observed. “There needs to be more joint industry projects and more collaboration, while still allowing for competition.”

Iyer noted that “subsea volumes are getting more modest” – a trend that will also necessitate more subsea tieback in the future. But he offered an optimistic note about future E&P campaigns in the US Gulf: “The deepwater Gulf of America will have a role to play in the future.” He cited a Wood Mackenzie study which indicated that “less than half of the reserves in the Gulf have been produced.”