SLB OneSubsea has been awarded the subsea production systems contract for the first phase of Rovuma LNG offshore Mozambique, adding another long-lead equipment package as the Area 4 partners progress the project towards a final investment decision.
The contract was awarded by ExxonMobil Moçambique on behalf of partners ENH, CNPC, Eni, KOGAS, and XRG. OneSubsea’s scope covers subsea trees, manifolds, umbilicals, associated control systems, engineering, procurement, manufacturing, and installation services for the deepwater gas development.
The equipment will support an upstream system planned around 18 initial subsea wells feeding gas from the Rovuma Basin to an onshore liquefaction complex. ExxonMobil’s current design calls for wells in water depths of up to around 1,700m and approximately 50km of offshore flowlines connecting the development.
Subsea production equipment provides the interface between each reservoir well and the gathering system. Trees installed at the wellheads control production and provide access for monitoring and intervention, while manifolds combine flows from several wells before gas enters the subsea pipeline network.
Umbilicals carry the electrical power, communications, hydraulic services, and chemicals required to operate equipment on the seabed. At depths approaching 1,700m, reliability becomes central because routine physical access is impossible and intervention requires specialised vessels, equipment, and planning.
The OneSubsea award follows a series of contracts placed by the Area 4 partners before final investment decision. ExxonMobil announced approximately $1.1 billion of pre-investment awards in August for long-lead upstream equipment and early site activity, including pipe, valves, and subsea production systems.
The commercial logic is to start manufacturing items with extended delivery schedules before the complete project enters construction. Subsea trees, large valves, line pipe, umbilicals, and control systems require engineering, specialist materials, manufacturing, testing, preservation, and logistics, and some cannot be produced quickly once the project reaches sanction.
Pre-FID procurement reduces schedule risk but does not remove project risk. Capital is committed while commercial, financing, regulatory, and execution work is still being completed, so the partners have to select equipment whose configuration is sufficiently mature to manufacture before the full project is sanctioned.
Earlier in September, the Area 4 partners selected a Saipem-Jan De Nul consortium for upstream engineering, procurement, construction, and installation work covering the 18 wells and their subsea pipeline and manifold network. Shorebase service contracts were also awarded to Mozambican companies for logistics supporting drilling and offshore operations.
Onshore, Rovuma LNG Phase 1 is designed around 12 electrically driven liquefaction modules, each rated at 1.55 million tonnes per year, giving total planned capacity of 18.6 million tonnes of LNG annually. A combined-cycle power plant will supply electrical demand for the liquefaction system.
ExxonMobil says the electric modular design can reduce greenhouse gas emissions by up to 40% compared with a conventional large-train configuration based on the project’s front-end engineering design. Most of the liquefaction modules are intended to be fabricated off site before assembly at the Afungi development area.
That modular approach shifts a larger share of manufacturing into specialist yards where production conditions can be controlled, while reducing some of the workforce and construction intensity required at the project site. It also increases the importance of transport, heavy lifting, interface control, and dimensional accuracy when modules manufactured in different locations are brought together.
OneSubsea has not disclosed the value of its contract. The company intends to establish a service base in Mozambique, creating local training and employment while providing support for subsea equipment through installation, commissioning, and operation.
Local capability matters because the subsea systems will remain in service for decades if the project proceeds. Maintenance planning, spare parts, technical support, and intervention expertise become part of the operating model long after the initial manufacturing contract has been completed.
The Area 4 partners are targeting final investment decision in 2026. ExxonMobil’s project material describes Rovuma LNG Phase 1 as an 18.6-million-tonne-per-year development with approximately 7,500 Mozambicans expected to participate during execution and around 700 jobs during operation.
The scale of the project creates significant coordination risk. Deepwater equipment, offshore installation, line pipe, onshore module fabrication, site construction, power generation, logistics, and commissioning all have to progress on compatible schedules. A delay in one critical system can hold a project even where most other packages remain on plan.
The OneSubsea award moves another long-lead element from project definition into engineering and manufacturing. Final investment decision remains the decisive milestone; if that proceeds, the contracts already placed will give Rovuma LNG a head start on equipment that would otherwise sit on the critical path to first gas and LNG production.
