The September quarter sales figure of $1.06 billion fell short of UBS's estimate of $1.13 billion, as an oil venture off the Western Australian coast under-performed. JPMorgan described the numbers as "a touch light".

However Santos maintained its full-year production forecast of a 52 million to 57 million barrels of oil equivalent, and at the nine-month stage output was 3 per cent ahead of the same time last year, at 39 million barrels. Importantly, construction of the company's flagship GLNG venture in Queensland remains on track, with production to begin in 2015.

Santos shares rose as much as 2.45 per cent in early trading on Friday to $12.95.

"On the sales revenue line it was a mix: less liquids, but more gas and LNG than we were expecting," said UBS analyst Nik Burns.

"It just meant the revenue numbers were lower [than we were estimating], but more importantly all the guidance remains unchanged for this year."

At the $US18.5 billion GLNG venture, construction is almost 90 per cent complete, chief executive David Knox said.

Santos still hasn't narrowed down the window for the start-up of GLNG, although its partner Total has signalled it is expecting production to get under way in the second half of 2015. JPMorgan analyst Benjamin Wilson said he was expecting Santos to finally refine the start-up date at a strategy day on November 26.

Mr Burns noted that Santos had indicated that gas to be used in the start-up process would reach the LNG plant in Gladstone by the end of 2014, putting it on track to begin production in the third quarter of 2015 given the process takes about 6 to 9 months. Santos said the second production train at the project would be ready for start-up at the end of 2015.

The ExxonMobil-led PNG LNG plant reached full capacity in late July and shipped 23 cargoes during the September quarter, boosting Santos's LNG production.

But that lift to Santos's output was partially offset by lower output from fields in the Carnarvon Basin in Western Australia "due to extended outages at customer facilities and lower nominations" as well as a planned one-month shutdown of the Darwin LNG project for maintenance. Sales were also affected by a 10 per cent dip in the average oil price compared with the corresponding quarter, while the production at the Fletcher-Finucane field offshore WA was halted in early September for repairs.

Production from Fletcher-Finucane should resume "in the coming week," Santos said.

Santos also reported the completion of eight development wells at the Hides field in PNG, which supplies the PNG LNG venture, and confirmed that the Hides Deep exploration well, an important potential supply source for what is expected to be a highly profitable expansion of PNG LNG,  started drilling in early October.

Production in the September quarter rose 4 per cent from a year earlier to 14 million barrels of oil equivalent.

For the first nine months for 2014, sales were 16 per cent ahead of a year ago, at $2.947 billion.