Unveiled late last week in the US, and mentioned briefly here on Friday, the document is called 2012 The Outlook for Energy: A view to 2040, and while much of it is predictable, the emphasis on gas is significant given Australia's rise as a gas exporter - and the latest shale-gas discovery news from China.

Key findings in the study, which is very much an exercise in crystal ball gazing to help ExxonMobil management with major investment decisions, include:

• Oil and gas retaining a 60% grip on total energy consumption in 2040
• Gas demand growing by more than 60% with an increasing share from unconventional sources such as shale formations
• Gas overtaking coal as the second biggest source of energy after oil
• Relatively slow growth of renewable energy sources other than nuclear and hydro

That final point about renewables makes for interesting reading in the wake of the Durban climate change talks which wrapped up yesterday, and while ExxonMobil said there would be "meaningful" growth in renewables it added that "advances in technology will be necessary to make these fuels more practical and economic".

By 2040, according to ExxonMobil's future-gazing analysts, modern renewables such as wind, solar and biofuels will lift their share of global energy demand from about 3% to 7%.

However, over the same time period of 2010-40 oil and gas will increase their share of the total world market from 55% to 60%, and when combined with coal (which will decline in demand for the first time ever), will see conventional fossil fuels continue to account for 80% of total worldwide energy demand.

Packed with graphics, the 43-page web version of the report is well worth a visit here.

What The Slug found especially interesting was the ultra-big picture scenario painted by ExxonMobil, and the fact that the world will become a much heavier user of gas over the next 30 years.

ExxonMobil chairman and chief executive Rex Tillerson said in his introductory remarks in the report that the world would need to expand energy supply "in a way that is safe, secure, affordable and environmentally responsible".

"The scale of the challenge is enormous and requires an integrated set of solutions and the pursuit of all economic options," he said.

One of the key numbers for quick consumption include a forecast that global energy demand will be about 30% higher in 2040 compared with 2010 as the world's population rises towards nine billion.

Other estimates include a forecast that energy use in advanced countries (essentially the western world) will remain "essentially flat" while demand in emerging economies will grow by close to 60%.

China, as is the case with many commodities, will be responsible for the lion's share of the fresh demand over the next 20 years, before slowing as its economy and population matures.

Not included in the ExxonMobil analysis, because it is very much a work in progress, is the latest shale gas news from China, which includes what appears to be the most significant discovery so far.

Royal Dutch Shell and its local partner PetroChina reported significant flows from 20 vertical wells drilled to test rock conditions in Sichuan province. Some of the wells are reportedly producing more than 10,000 cubic metres (353,134 cubic feet) of gas a day, though the real test will come from future horizontal drilling.

Commercial development of the Sichuan discovery could take some time, with a spokesman for PetroChina saying that the geological conditions appeared to be more difficult than those experienced in the fast-growing U.S. shale-gas sector.

However, news that China has made a major shale-gas discovery reinforces the view of the US Geological Survey that China will eventually be found to contain the world's largest accumulation of the unconventional gas - an estimated 1275 trillion cubic feet compared with the estimated 862tcf in the US.

Both of those numbers sit comfortably alongside the ExxonMobil view of the world's energy future, which will be increasingly gas-powered.

*First published in sister publication EnergyNewsPremium.net yesterday.