A system for steam-assisted gravity drainage for heavy oil production has a first well, a second well, a first platform connected to the well head of the first well so as to inject steam into the first well, and a second platform connected to the well head of the second well for producing heavy oil from the second well. The platforms are arranged in parallel flow relationship. Each of the platform has a first level with flow lines extending longitudinally therealong and a second level located above the first level and having piping connected to the flow lines of the first level. The second level includes valves and controllers cooperative with the piping. The platforms are modular in nature and can be connected to other platforms.