A lobby group that represents Canada's oil industry is still expecting the output from Canada's oil patch to almost double over the next two decades, but the growth is a little lower than previously forecast.

The Calgary-based Canadian Association of Petroleum Producers said in its annual forecast Monday it expects Canada to produce 6.4 million barrels of crude oil a day by 2030. That's almost twice as much as the 3.5 million barrels a day the country produced last year, but not as much as the 6.7 million barrels a day the agency previously thought would be produced by 2030.

The drop of 300,000 barrels a day represents a reduction of 4.4 per cent.

The agency is still expecting growth in both segments of the market — the largely untapped oilsands, and also conventional oil deposits. While increased activity from the Athabasca oilsands basin is no surprise, an increase in output from conventional oil in the coming decades is a bit unexpected.

But the agency credits new technologies for the uptick."Conventional oil production continues to reverse its previous long decline because of the continuing use of horizontal and multi-fracturing drilling techniques."

Activity in Canada's oilsands is expected to expand drastically, but CAPP says the pace of growth is slowing as companies run into much higher costs, attributing the slowdown to "cost competitiveness and delays in project schedules."

French multinational oil conglomerate Total SA last month shelved its Joslyn project, an $11-billion oilsands development that was supposed to come online by 2020, because of cost overruns.

Projects in Western Canada are also dealing with a recent spike in natural gas prices, which is the energy source that's powering much of Alberta's oil activity.

As it stands, Canadian oil sells at a discount to its U.S counterpart because of supply issues, and the fact that Canada's oil is largely dependent on being shipped to refineries abroad for processing. 

All that new oil may only exacerbate a growing mismatch between the oil being pumped, and getting it to market. As politicians, corporations and environmentalists clash over building new pipelines, oil-by-rail has quietly grown to be a shipping alternative, causing its own set of bottlenecks as other shippers say all the railcars are being diverted to carry crude.

In its report, CAPP says that trend won't abate any time soon, as it expects the rail industry to ship 700,000 barrels of Western Canadian oil a day by rail by 2016. That's an exponential growth rate from the amount of crude that has historically been moved by train in Canada.