Shell Offshore has made a final investment decision (FID) on a sizeable oil and gas project offshore Louisiana. It is expected to recover more than 240 million BOE over its lifetime.
The Sparta development straddles four blocks in the Garden Banks protraction area in about 1400-m water depth located approximately 275 km off the Louisiana coast in the US Gulf of Mexico (GOM).
The development features eight subsea production wells and two subsea drilling bases connected via two production loops to a newbuild floating production unit capable of producing up to 90,000 BOE/D. Sparta will be Shell’s 15th GOM deepwater host and will begin production in 2028.
Sparta’s design closely replicates the 100,000 BOPD Vito and Whale designs, which are four-column semisubmersible host facilities. Vito is in the greater Mars Corridor and began production in February 2023. Whale, destined for the Perdido Corridor, is set to come online in 2024.
Shell called the development approach for Sparta an “enhanced replication of Vito and Whale,” with Sparta replicating about 95% of Whale’s hull and 85% of Whale’s topsides.
"There are differences related to what we learned at Vito and what we've learned in the construction of Whale," said Rich Howe, executive vice president of deep water for Shell. "There's continuous improvement, with some differences in the Sparta design related to carbon. While Vito was a very low-carbon intensity project, Sparta will be less than half of Vito's carbon intensity in terms of emissions."
Helping to accomplish this will be the all-electric topsides compressors utilized on the Sparta floating production unit (FPU), the first of its replicable projects to feature this type of equipment, according to Shell.
Sparta also marks Shell’s first development in the GOM requiring 20,000-psi-rated equipment. This is typically referred to as a “20k” development. "It is a high-pressure reservoir flowing back to the host," said Howe, noting that it will require, for example, "different SURF systems, different boarding valves, and different chemical injection systems."
The Sparta FID caps off a busy year for the company in the GOM. In addition to first oil at Vito, the company saw the delivery of the Whale FPU by Singapore's Seatrium, FIDs at Dover and Great White, and secured full ownership at Kaikias. According to Howe, these project milestones reflect the fact that the company is committed to a long-term footprint in the GOM.
“We think that we've got some differentiated capabilities, like in drilling—where we can get high-quality, safe, low-cost wells that are unique to Shell,” he said. “All of these projects underscore our appetite for accretive growth in the Gulf of Mexico where we can demonstrate competitiveness.”
New Neighborhood
While the possibility of applying the simplified, replicable host approach is one of the reasons cited by Howe as to what attracted Shell to the Sparta development, the other three reasons speak to the long line of explorers and developers of the discovery when it was known as North Platte and to the location itself.
"At first, what attracted us to Sparta is that, through the course of time, those developers discovered a lot about the reservoir," he said. "When we finally had our shot, we understood much more about the subsurface, which made it pretty attractive to Shell. Also, I think Equinor made Sparta interesting. They're a great company and a great partner. We worked with them at Vito, and there's much to like there."
Discovered in 2012 by Cobalt Energy and Total, the Wilcox-aged discovery requires 20K- psi technology to develop, according to the partners. Cobalt’s stake in the asset was sold to Equinor when the company went bankrupt in 2017. TotalEnergies, in early 2022, walked away from the project, leaving Equinor with 100% interest.
Shell purchased 51% of Equinor’s interest in the North Platte deepwater development project and became the new operator of the field in August 2022. Equinor retained a 49% interest in the project. The partners agreed to rename North Platte to Sparta.
And the third, like in real estate, is all about the location, location, location.
"This whole corner of the Gulf of Mexico is underexplored and relatively undeveloped; this inboard Paleogene play is an up-and-coming zip code. We will build our house here early in the neighborhood, creating a strategic competitive advantage in that corner of the Gulf of Mexico."
