Rockhopper falls nearly 20% in London while reaffirming Sea Lion

Rockhopper Exploration shares fell 19.28% in a session on the London Stock Exchange after the company reaffirmed that it would proceed with the Sea Lion oil development in the area of the Falkland Islands. According to news reports, the decline adds to a loss of nearly 32% over the past month. The share price movement coincides with the persistence of political, legal and operational risks surrounding the project, but the sources do not allow the fall to be attributed to a single cause.

Sea Lion: stakes, production and planned timelines

Rockhopper owns 35% of Sea Lion, while Israel’s Navitas Petroleum, which operates the project, holds the remaining 65%. The plan calls for development drilling to begin in 2027 and production to start in the first quarter of 2028. These are dates planned by the companies, not results already achieved.

For the first phase, the consortium plans to use the Aoka Mizu floating vessel and drill 11 wells. Estimates cited in news reports put initial production at around 50,000 barrels per day. A later phase could add another floating unit, the OSX-1, with a final investment decision scheduled for 2028 and production projected to begin in 2030. The companies say that the two units could increase output to 180,000 barrels per day; that figure is a target, subject to the project’s development and performance.

Consulting firm Netherland, Sewell & Associates estimated 314 million barrels in proved and probable reserves. Rockhopper also reported that a USD 200 million capital increase would provide it with funding through mid-2028. This figure relates to the financial position reported by the company and does not, by itself, establish that all future phases are funded.

Questions about the estimates and expansion

Argentine petrophysicist Juan Carlos Glorioso questioned some of Sea Lion’s technical and economic assumptions. According to his analysis, recovering the reserves attributed to the project would require extracting nearly 14 million barrels per well, at an estimated cost of USD 36 million per well. Glorioso argued that the available public information does not support considering these per-well figures reasonable.

The specialist also noted that resource estimates remain uncertain until wells demonstrate their performance. In his view, expansion will depend on the results of the first phase and will require new investment. His observations are an expert assessment of the disclosed assumptions, not verified production results. Nor do the available sources make it possible to determine in advance whether the project will achieve the announced volumes.

Sovereignty dispute and Argentine measures

Sea Lion is being developed in a territory and maritime areas over which Argentina claims sovereignty and which the United Kingdom administers. The Argentine Government considers exploration and exploitation activities carried out without Argentine authorization to be illegitimate. In this context, it has pursued judicial and administrative proceedings against companies linked to the project, as well as measures to tighten the sanctions regime, which also affects shareholders and suppliers.

News reports also say that Argentina initiated an arbitration procedure under the United Nations Convention on the Law of the Sea and could request provisional measures. Any involvement by courts and the scope of the actions will depend on the relevant proceedings; they do not amount to a confirmed suspension of operations.

For companies and suppliers, the case involves risks of different kinds: exposure to share-price movements, the availability of specialized services, and possible consequences of Argentine measures. Rockhopper’s announced continuation of the project reflects the company’s position, while the schedule, funding for later phases and technical viability remain subject to execution and verification.