What will happen to Quebec when Albert's stops becoming a funder of equalization payments and dare I say starts being a receiver.
Preamble:
Equalization is designed to "equalize" the quality of services every Canadian receives, it is calculated largely against the "fiscal capacity" of province (their ability to generate tax revenues).
The average fiscal capacity of all provinces is being pushed upwards by "have provinces" and downwards by "Have not provinces".
Quebec is slightly under the Canadian average but because it has a huge population, it receives the biggest total amount while receiving the smallest "per capita" amount.
Now to your answer
Equalization is financed by the Federal revenues gathered in all 10 provinces and 3 territories. Alberta accounts for roughly 15% of all Federal revenues. Quebec contributes 20% and Ontario more than 40%. The rest of Canada contributes the other 25-26%
If the oil industry were to collapse completely, Ottawa might lose 4% to 5% of its total revenues. Let's imagine that Ottawa loses 10% of its total revenues as a worst case scenario after the oil collapse (That would mean a 20% to 25% unemployment rate in Alberta, which is quite doubtful) and accounting for Equalization representing 6% of Ottawa spending... then Ottawa would have no more money for Equalization.
The effect on Quebec
Losing $13 billion out of the $113 billion in revenues and $107 billion in expenses, Quebec would have to constrict its expenses by $7 billion or increase its real GDP by $47 billion (currently $417 billion) so a 1.1% in economic growth.
It would pinch but not kill.
The effect on Alberta
Loss of ~$3 in royalties, ~$4 in income taxes due to high unemployment and loss of oil corporate taxes and an increase in public spending of ~$5 to $10 billion again due to 20% unemployment would create a structural deficit in Alberta of over $12 to $17 billion a year, within 15 years Alberta would owe more in public debt than Quebec. This is because the Alberta government spends more per capita on programs than Quebec.
This will cause Alberta to have to increase income and corporate taxes and create a sale tax.
What the reality would be
Equalization is calculated as a percentage of Canadian GDP, the loss of the oil industry would lower the GDP of Canada and thus lower the amount in Equalization given to the provinces. This will force Ottawa to constrict all of its spending but to maintain Equalization at a lower level.
Quebec could expect to lose maybe half of its current Equalization and Alberta could expect to receive $2 billion to $3 billion in Equalization.
The real consequences on Alberta
A 25% unemployment rate is unrealistic, the place would catch fire way before that.
Under the assumption that the oil industry collapses, for Alberta to implement a %10 sale tax and raises income taxes by a few percentage points, under a worst case scenario, it would reach fiscal equilibrium within a couple years.
But things won't happen like that
Instead the reduction in demand for oil will be a slow process, each year cutting a little bit more out of the province's revenues and each year people will have to look for other jobs.
What Alberta will hopefully do is to gradually introduce a sale tax, raising its rate a little every year and then use the surplus to invest in diversification, education and innovation (like Norway is doing right now).
The worst thing Alberta could do
Is to sit on its ass and maintain the current lever of program spending (the highest per capita in Canada) and low taxes and hope the good 'ol days will come back.