Tuesday, April 12, 2016

Alberta Tar Sands Spring Leaks

Canadian regulators have quietly released a report blaming an operator for
uncontrolled leaks in the heart of Alberta's tar sand deposits.  Regulators say that the company, Canadian Natural Resources Ltd., injected too much steam underground attempting to extract ever deeper deposits of bitumen. The mistakes coupled with complex local geology caused the crude to bubble to the surface through faults and fissures instead of up recovery wells. About 80% of remaining deposits are deep underground and require enhanced recovery methods utilizing steam injection to gather. The government report highlights the risks of using high pressure steam injection to release the bitumen from these deep deposits.

One of the four leaks discovered in 2013 proved to be deadly to wildlife. Viscous crude leaked to the surface poisoning a small lake.  At least two beavers, 37 birds, 87 frogs and 22 small mammals were killed, covered in black goo. Dozens of more animals were rescued and cleaned. The company had to drain the natural pond. Despite spill remediation, crude continues to leak out of small fissures which according to the company, "are too small to measure". An estimated 6,600 barrels of bitumen have escaped to poison the environment to date.

While the company investigation blamed well failures, the Alberta regulators disagreed with that conclusion. Their report primarily blamed the effect of the company's high-pressure steam injection on the local geology that caused cracks to open up allowing bitumen to flow upwards wherever it could. Alberta Energy Regulator took three years to conduct its investigation at the company's Primrose facility. Its report was published last month. The company was warned once before in 2009 about using too much pressure. Then the Regulator issued new rules on allowable steam volume at Primrose. More rules have been issued this time including a ban on steam injection within 1,000 meters of an existing leak. The facility is one of six that uses cyclic steam stimulation, three are in various stages of development; all are owned by different companies.