The giant Kashagan oil field in Kazakhstan has moved one step closer toward first production with the introduction of gas into its offshore facility, the field's operator said in a statement Wednesday.

The North Caspian Operating Company, or NCOC, said that employing sulphur-free gas followed by the pressurization of its offshore installations and the completion of dynamic testing were critical steps ahead of the start of production.

Due to the great size and complexity of the project, the start-up of oil production at Kashagan requires a long sequence of steps, progressively ramping up oil output NCOC said.

The first steps in this sequence began at the end of June, but NCOC has given no exact date when first oil is expected to flow from the field.

The company said that in the coming months production would progressively rise from 180,000 barrels a day in the first stage to 370,000 barrels a day in the second stage.

Kashagan is a joint venture between Kazakh state energy company KazMunaiGaz, Eni SpA (E), ExxonMobil Corp. (XOM), Royal Dutch Shell PLC (RDSA, RDSA.LN), France's Total SA (TOT), ConocoPhillips (COP) and Japan's Inpex (IPHXY, 1605.TO).