Oilsands Review - September 2006

ENVIRONMENT 85

River lease. If the material isn’t fit for spreading, it’s sent to a landfill.

The Pembina Institute, a Canadian environmental think tank, hasn’t historically condoned the spreading of drill cuttings on land.

“There’s a risk of heavy metals seeping into the soil,” says Mary Griffiths, a senior policy analyst with the institute. “We need to make sure that cuttings don’t contaminate groundwater.”

She says she doesn’t know enough about the EnCana and Petro-Canada initiatives to comment, though they “sound interesting.”

Griffiths advocates suitable landfill practices but acknowledges their inherent weaknesses: “Even landfills with the best-quality liners will leak over time. But a leak-aid collection system under the landfill can help there.”

Petro-Canada also has its own brand of drilling-mud base fluid, a substance it describes as “clear like water, virtually nontoxic, and environmentally friendly.”

The company says that using the fluid allows for cuttings to be left on-site in most cases, “eliminating expensive land farming or special treatment.” The fluid is a blend of synthetic isoalkane fluid and severely hydro-cracked, low-toxicity mineral oil. First tested on Petro-Canada’s own leases, the substance is “more fish friendly” than diesel-based alternatives and makes for “faster, cleaner, and safer cleanup,” the company claims.

PHOTO: Joey Podlubny

Overseas, Shell UK Ltd. has entered into a partnership with TEG Environmental Plc to “investigate opportunities for the composting of oil-based mud drill cuttings,” according to TEG.

“It appears to compost very well, and composting is not new for oil and drill cuttings,” TEG chief executive Mick Fishwick tells the Scotsman. “The technical principle is very well established.”