Shell Canada says the Quest carbon capture and storage project north of Edmonton has reached the milestone of five million tonnes of stored carbon dioxide, equivalent to the annual emissions of about 1.25 million cars.

Two energy companies whose deal over aging assets in Alberta failed to win approval from the province's energy regulator over environmental concerns say they will try again.

Alberta's energy regulator has cited clean-up concerns in blocking the sale of sour gas wells, pipelines and other facilities from an energy giant to a much smaller company.

A boost in output from oilsands mines formerly operated by Shell Canada has sparked a $70-million expansion at a Shell oilsands upgrader, the president of Canadian Natural Resources Ltd. reported Thursday.

A group tasked with cleaning up Alberta's thousands of abandoned energy facilities says the province's rules to make sure polluters clean up their wells before selling them off are inadequate.

Founding members include Suncor Energy, Imperial Oil and Shell Canada, as well as the World Wildlife Fund, and federal and Alberta government representatives.

The possible transfer of hundreds of sour gas wells, pipelines and other facilities from energy giant Shell to a much smaller company has raised concerns about Alberta's efforts to ensure taxpayers don't get stuck with the cleanup bill.

In Alberta, the oil and gas sector is making efforts to reduce its environmental impact, however the industry still faces rising greenhouse-gas emissions.

John Horgan says he's hopeful the larger oil and gas companies will eventually share their retail and refining margins with the provincial gas price inquiry.

Shell Canada says the Quest carbon capture project near Edmonton has reached the milestone of four million tonnes of stored carbon dioxide, equivalent to the annual emissions of about one million cars.