The first gas from its own reservoirs arrived on Statoil's Åsgard B platform in the Norwegian Sea over the weekend.
Production is now flowing from the Midgard deposit via one subsea template, and the B platform is expected to reach planned output from this reservoir by mid-October.
The first export gas was also introduced to the Åsgard Transport trunkline, which runs to Statoil's treatment complex at Kårstø north of Stavanger.
Almost seven million cubic metres of gas per day will be sent to Kårstø during the start-up phase, reports platform manager Rune Hansen.
This output is due to be stepped up gradually, reaching around 18 million daily cubic metres on 15 October if everything goes as planned.
"Platform testing and commissioning have gone well so far, although challenges are still appearing which need to be resolved before stable production is achieved," says Mr Hansen.
"We still have a number of parallel critical activities to complete, and these could set us back."
Plans call for the Smørbukk deposit to be brought on stream on 1 November from two subsea wells.
The expanded gas treatment facilities at Kårstø are ready to receive gas from Åsgard. Capacity has been doubled to roughly 60 million cubic metres per day.
Output flowing from Norwegian Sea fields – Åsgard, Heidrun, Norne and Draugen – will fill about 40 million cubic metres of this capacity.