The foundation Wheatstone–Iago subsea system comprised nine development wells tied to the central Wheatstone Platform. Four Wheatstone manifolds were designed for up to 20 well connections, while the Iago wells and their flowlines form part of the same gathering system. The platform also receives production from the Julimar–Brunello development, whose subsea wells and manifolds connect through dedicated flowlines and control umbilicals. Production reaches the platform through risers supported by the fixed structure. The topsides perform initial offshore treatment rather than full LNG processing. Installed functions include inlet separation, removal of free water from gas, dewatering of condensate, compression, metering and handling of monoethylene glycol used for subsea hydrate control. Dehydrated gas and dewatered condensate are recombined for export, while produced water is treated offshore. Supporting systems include chemical injection, pigging, flare and pressure relief, electrical generation and distribution, process and subsea controls, fire-and-gas detection, emergency shutdown, firewater, seawater lift, telecommunications and accommodation. The approximately 37,000-tonne topsides were installed by float-over onto a steel gravity-based substructure fixed to the seabed and protected by ballast and scour material. Export is through the 44-inch Wheatstone trunkline, approximately 225 kilometres long, which lands at Ashburton North near Onslow. The stream is processed at the onshore Wheatstone plant into LNG, domestic gas and condensate. Domestic gas enters the Dampier to Bunbury Natural Gas Pipeline. The offshore platform has no hydrocarbon-storage or tanker-loading system.