Gas shut-in to conserve bitumen

Alberta’s energy regulator has expanded its shut-in of natural gas wells in favor of protecting the value of oil sands bitumen.

The Energy and Utilities Board stopped production from 121 wells representing 42 billion cubic feet of natural gas. EnCana owns 120 of the wells and Canadian Natural Resources the remaining single well.

The board determined that gas production has lowered pressure in the geological zones of bitumen below the gas layers.

It said the situation could endanger eventual recovery of the bitumen deposit, which is estimated to be 50 times larger than the shut-in gas.

Four years ago, the board halted gas output from 900 wells, holding reserves of 280 billion cubic feet, to protect 25.5 billion barrels of bitumen with a value 500 times greater than the affected gas.

It is now looking at whether gas production should be curtailed in other regions, although details of a potential review are still being developed.

EnCana, which is also an oil sands producer, said it needs to review the ruling before making a comment.

—Gary Park