Total Canadian oilsands production is projected to approach 4 million b/d by 2030, nearly 1 million b/d more than current output, though the rate of growth is set to slow compared to previous years, according to a new 10-year production forecast published by IHS Markit.

The firm expects Canadian oilsands output to average 100,000 b/d of year/year growth over the next decade, down from a growth rate of more than 150,000 b/d over the current decade.

Transportation constraints, including a lack of adequate pipeline capacity, have created price uncertainty for producers and discouraged new large-scale incremental investments in oilsands development, according to Kevin Birn, IHS Markit’s vice president, who heads the firm’s Oil Sands Dialogue.

“Large-scale oilsands projects take two, three, four or more years to be brought online, and so the reality of a slower pace of investment and growth in the Canadian oilsands is taking shape,” Birn said. “Yet, ironically the call on Canadian heavy sour crude oil — the principal export from the Canadian oilsands — has never been greater as the rapid deterioration of Venezuelan output tightens the supply of heavy sour crude globally.”

Over the next decade, instead of coming from new projects, Canadian oilsands growth will mostly derive from existing projects and facilities, according to IHS Markit. Two-fifths of the firm’s projected production increase by 2030 will come from a ramp-up of projects recently completed or under construction.

Meanwhile, IHS expects close to a quarter of growth to come from projects on hold but “where some construction or site clearing has already begun,” as well as from “debottlenecking of existing operations.” Less than a third of the expected growth will come from new projects, according to the firm.

Birn said Canadian oilsands still carries upside, even with current projections for slower growth.

“The key to unlocking further upside growth potential in the Canadian oilsands will be the ability of the government and industry to restore confidence that the crude oil produced in western Canada can get to markets at a reasonable transportation cost,” Birn said.

The latest growth projections come as new Canadian oil export projects like Enbridge Inc.’s Line 3 pipeline replacement continue to face regulatory hurdles. Earlier this week, a Minnesota legal verdict ordered additional environmental review for Line 3, raising fears that the one-year delay already holding back the $9 billion project will grow longer.