courtesy Nexen Inc.

Oil sands companies quoting the value of their reserves may be booking the lower winter values of their bitumen heavy crude for the last time, judging by the new U.S. Securities and Exchange Commission reporting changes for oil companies.

Heavy oil producers traditionally book the value of their business at the end of the December at the spot price. At present, that’s $25 a barrel for heavy crude.

But the new rules at the SEC suggest a 12-month average price for booking proved and probable reserves will be available for December 2009 reporting.

Heavy oil — the stuff steamed out of oil sands before upgraders go to work — has been in high demand this year across North America. Good prices have helped oil companies justify putting off the expensive work of building heavy oil upgraders.

Due to holiday absenteeism, Scandoil.com was unable to secure meaningful comment on our story from an oil sands player.