Canadian interests will make another try at evaluating deeper light oil potential beneath the vast Athabasca tar sands.
They plan to re-enter a 5,500-ft well on the west outskirts of Fort McMurray, Alta., and production test five zones that had oil or gas shows during the original drilling effort in 1994, which stalled for lack of funds.
The well, AOC 7-32-89-10w4, had shows at 2,580-2,680 ft, 2,900-3,000 ft, 4,690-4,790 ft, 4,850-4,950 ft, and 5,450-5,500 ft TD, said Robert O. Russell, a Calgary geologist whose consulting firm Akan Oil & Minerals Ltd. is involved in the project. Burnish Enterprises Ltd., Calgary, has the workover rig contract.
Top of granite in the well is at 1,781 ft, and the bottom 20 ft of the hole is in gabbro. Casing was set to 1,962 ft.
The operator, Uranium Power Corp., Vancouver, BC, public company, said that if the tests prove noncommercial it plans to deepen the well to the primary target, a large 2D seismic feature at 7,200 ft. If production were established, UPC would drill a step-out well to the deeper feature.
UPC put costs at $170,000 (Canadian) for tests, $50,000 for completion, and $500,000 for deepening.
The 1994 drilling was carried out in a cooperative venture between Aabbax International Financial Corp., Archean Corp., and Industrial Coal & Minerals Ltd. They called it the first North American well to target Precambrian granite as a potential hydrocarbon source.
The Athabasca tar sands is one of the world's largest oil deposits with 1.3 trillion bbl in place across 28,000 sq km. Calgary geologist C. Warren Hunt theorizes the oil leaked through fractured granite from a deeper source and into the McMurray sands and became biodegraded.
Hunt advances the idea that a trough or graben identified on seismic could have prevented the upward release of part of its original bounty of light oil, which may now be trapped in fractures and unconformities in the granite. To test the theory, he formed Anhydride Oil Corp. (AOC), now owned by UPC.
Russell and Hunt point out that oil occurrences are known in granite in 20 countries, several of which have produced significant volumes of oil.
Granite has been documented to contain "so many unconformities" that the term "granite" appears to be a misnomer, Russell said. In several decades of studies he has found intercrystalline porosity as high as 23% in granite in which formation water has dissolved the feldspars.
Some unconformities contain water in great quantities and fresh enough to be used for irrigation, he said.
