OREANDA-NEWS. October 17, 2011. Ever since an oil well near Leduc, Alberta, made Canada a significant oil producer in 1947, the energy export business here has relied almost entirely on the United States.

Thanks to the massive oil sands of northern Alberta, Canada is now the United States’ top supplier of foreign oil. But that may be changing.

China’s growing energy needs and the prospect that an environmental backlash in the United States against the oil sands might hinder access to Canada’s traditional market are making the idea of a trans-Pacific market for Canadian oil increasingly attractive.

Change is about the only constant in the rapidly shifting global energy business. And one of the most significant changes is the seeming role reversal between what was once considered the periphery of energy production and consumption and what was considered the center.

That change is starkly visible in the relationship between China and Canada.

While Canada — and the United States, for that matter — have long been major energy producers, the largest role that the West has played in the global energy market has been as leading consumers.

Under the old paradigm, the nations of the Middle East were the chief producers. Institutions like the Organization of the Petroleum Exporting Countries and the International Energy Agency, over time, entrenched that dynamic.

But just as the institutions of Bretton Woods, byproducts of a U.S.-dominated postwar economic order, are being challenged, so are OPEC and the I.E.A., their relevance questioned in a new era marked by the ascendence of Brazil, China, India and Russia and the relative stagnation of the West.

If the periphery has not yet become the center of both energy production and consumption — and production is increasingly outside the grip of OPEC and the I.E.A. — then the traditional roles are at least under stress.

While the rise of China as a major market for Canada’s oil is far from assured, there are growing signs of interest from Beijing. Over the past three years, several Chinese state-owned oil companies have opened offices in the corporate hub of the Canadian energy industry — Calgary, Alberta — and have invested about USD 10 billion in the country’s oil industry.

“Until recently, energy was seen in continental terms. Now the bloom is off the rose of a just-continental policy,” said Paul Evans, the director of the Institute of Asian Research at the University of British Columbia in Vancouver, who grew up in an Alberta oil patch where his American-born father was in the business.

“Canadians are divided, but they generally see China as an opportunity. The concept of seeing energy in a global context rather than a continental one can be sold,” Mr. Evans said.

Many factors, particularly political ones, could ultimately upset any shift of oil exports away from the United States to China; but economics is probably not among them.

Many environmental groups in the United States are using a proposed pipeline expansion, which could bring oil sands production to U.S. refineries on the Gulf of Mexico, as a reason to impede further development of the oil sands.

Because it would cross an international border, the Keystone XL project requires presidential approval. This month, opponents of the pipeline provoked arrests outside the White House to draw attention to the issue. Lobbying efforts and protests by environmentalists have since escalated.

A study done as part of a U.S. Department of Energy review concluded that it would be less expensive to send crude from the oil sands to Canada’s Pacific coast by pipeline, and from there to Asia by tanker, than it is to move it entirely by pipeline to the Gulf Coast.

The catch is that the current pipeline to Canada’s west coast, which sends a small portion of the oil sands’ production to Asia, is already operating near capacity. Its owner, Kinder Morgan, has expansion plans.

And in January, Canadian regulators will begin reviewing plans by Enbridge, a major Canadian pipeline operator, to build a second line to the coast. An early investor in the project, which is worth 6.6 billion Canadian dollars, or about USD 6.35 billion, is China Petroleum & Chemical, also known as Sinopec.