The cause of Gazprom being forced to eat a hefty price discount from its once captive European customers is a combination of surplus energy sloshing around the world courtesy of the US shale gas revolution and appalling past business practices by the Russians.

It is drawing a long bow but it is possible to see a similar situation develop in the oil market where similar characteristics can be seen.

There is an overconfident cartel and a customer base which would be delighted to deliver a painful blow by sourcing energy elsewhere.

Breaking OPEC will be much harder than it was for the Europeans to break Gazprom, though the lesson is there for everyone to see, with little Bulgaria extracting a 20% price discount from the Russian company that is both state-controlled and has a monopoly on gas exports.

Other European countries are copying Bulgaria in demanding a discount on the gas they buy from Gazprom, as well as taking precautionary steps such as sourcing more gas from reasonable and reliable suppliers, such as Norway, in building LNG receiving stations and in encouraging exploration for shale gas inside their borders, which is what Poland is doing.

However, behind the individual situations of winners and losers in Europe there is a much bigger picture emerging and that is the overall energy supply situation in a post Peak Oil world. This is a place where energy is in abundant supply, not the shortage predicted.

The US shale gas industry is one part of the "energy flip" from shortage to surplus.

Other factors include a worldwide economic slowdown, the rising use of renewable energy sources such as wind and solar and the remarkable comeback of coal since its price fell sharply and it became the preferred (low-cost) fuel in a capital constrained world.

OPEC has felt the first chilly blast of what happens when the whip hand is transferred from supplier to consumer.

Since the oil price peaked in 2007 it has gone nowhere, hovering between $US90 a barrel and $110/bbl, depending on whether you are looking at the Brent or West Texas Intermediate price.

On an after-inflation basis (and after the sharp rise in capital and operating costs of all natural resource projects) it could even be argued that the real return to members of the OPEC cartel has been in decline.

Will that trend continue? That is the question which interests The Slug because it is possible that the energy world is undergoing a long-term change thanks to supply adequately meeting demand and other sources of supply being introduced that could produce an overall energy glut.

Coal, for example, appears to be the sick man of the energy world because it is disliked by environmental activists and governments alike.

However, over the past year the global rate of coal consumption has risen, not fallen, because it has become the low-cost fuel of choice for electricity generators.

At Gazprom, this week's Slugcatcher case study, there is a remarkable trend of decline emerging. This trend can, in part, be traced to the Russian gas-export monopoly's appalling treatment of Eastern European customers in 2006 and 2009 when it cut off supplies in the depths of winter.

That action, a variation of the OPEC oil embargoes of the 1970s, sent shockwaves through Europe as it realised the folly of having its energy supply controlled by an aggressive Russia that was using gas as an economic weapon.

Big changes have occurred and are continuing to occur.

LNG imports into Europe have risen, partly thanks to the building of more receival stations and partly because cargoes from exporters such as Qatar have been redirected away from an increasingly energy-independent US.

The US, in turn, is exporting more of its surplus coal to Europe because its coal mines are being squeezed by the dramatic increase in shale gas production.

There is more of the same to come because anyone who imagines that the US is the only country with commercially viable reservoirs of shale gas has not considered the history of global oil production, which started in a few locations and then spread.

Shale gas will follow a similar pattern.

The Russians, in keeping with their arrogant way of treating gas customers, are refusing to accept the shale-gas challenge.

Gazprom chief executive Alexei Miller told a television interviewer in late March that "the shale gas bubble will burst very soon. We are sceptical about shale gas. We don't see any risks at all".

So said the man who was also forced to report a 9% fall in gas sales to Europe and a 15% fall in profit for 2012, as once-captive customers turned to reliable and reasonable energy suppliers.

Gazprom's problems are the same as those suffered by any monopoly that abuses its market power.

In time, if the energy worm continues to turn, OPEC members will be next to pay a heavy price for decades of market-power abuse.