Australia will be a prime focus for Shell as it integrates its $91 billion BG Group takeover, expected to be finalised next year, and cuts 2800 jobs from the pair's combined global workforce.
Merger documents released yesterday by the oil major show it is hunkering down for a prolonged oil-price downturn and is taking further measures to cut costs and reduce spending.
While the majority of job -losses are likely to be in the pair's London head offices, Shell's local Perth headquarters and BG's Brisbane corporate offices are also expected to be in the firing line. 
"The combined group's future prospects will, in part, be dependent upon the combined group's ability to integrate the Shell Group and the BG Group successfully and completely," Shell said in a merger circular.
"Value delivery from a number of key jurisdictions, including the BG Group's assets in Australia and Brazil, as well as integration of the BG Group's LNG shipping and marketing business and trading activities and successful execution of the substantial disposals that the combined group is expected to make following completion of the combination are, in particular, critical to the overall success." Shell's Perth office has about 600 people and BG's Brisbane headquarters had 900 people after cost-cutting last year.
In Brazil, Shell has mainly downstream retail petrol and ethanol assets, while BG has deepwater oil, meaning the crossover of jobs is expected to be less than in Australia, where both BG and Shell are focused on LNG.
The oil major says it is too early to give details of its integration plans. It is unclear -whether Shell wants Perth, Brisbane or somewhere else as its eventual Australian corporate headquarters after the merger, given its biggest operating asset will be the Queensland Curtis LNG plant at Gladstone, which processes coal-seam gas from thousands of onshore coal-seam gas wells.
Its only operated West Australian asset is the Prelude floating LNG vessel planned to anchor 475km northeast of Broome in the Browse Basin from 2017, while the Browse floating LNG project it is investigating with Woodside looks unlikely to go ahead in the near term with oil prices at -current levels.
A Shell spokesman would not comment on the location of the merged group's Australian headquarters.
Shell's latest update on the transaction, which has cleared major regulatory hurdles and will face shareholder votes from both parties in late   January, came with a warning that the recent slide in oil prices highlighted the fact that the downturn could last "several" years.
"Our industry has entered into what could be a prolonged oil price downturn," Shell chief Ben van Beurden said yesterday.
Shell lowered its 2016 capital spending plans by $US2bn to $US33bn and said it would pursue further cost-cutting next year.
Oil prices, trading yesterday near 11-year lows around $US36 a barrel, need to rise if the transaction is to work for Shell.
The net asset value break-even oil price is in the low $US60s and prices need to be $US50 or higher next year for the deal to boost cashflow in 2016.
The fall in crude prices has exacerbated fears that Shell is paying too much for BG, despite unanimous approval from both boards.
Philip Lawlor, the chief investment strategist at Smith & Williamson Investment Management, which owns shares in Shell and BG Group, said that if oil prices fell to about $US25, the deal could collapse.
"They are very reluctant to walk away, but there must be a level at which they would do so," he told The Times in London.
Two of the biggest BG shareholders have sold nearly Â£300m ($615m) of shares in recent weeks, in a sign of rising unease over the takeover.
Axa Investment Management has sold 18.4 million BG Group shares worth Â£168m, cutting its stake by nearly two-thirds since   October. Wellington Management, an American hedge fund, has sold 11.82 million shares, worth more than Â£108m and a third of its holding, since   September 30.
Another fund manager said that Shell was lobbying hard to ensure support for the deal and, with only 50 per cent approval required, said that it was "very difficult to see how the deal could be blocked".
Shareholders including Aberdeen Asset Management, Old Mutual and Henderson are understood to support the deal .Additional reporting: The Times