History of The Petroleum Industry in Canada (oil Sands and Heavy Oil) - In Situ Recovery

In Situ Recovery

The oilsands projects just described are unique in the world: They exploit near-surface bitumen from open-pit mines. The industry has also spent decades experimenting with ways to recover bitumen from deeper deposits. The only way to develop petroleum resources underground is through in situ production techniques.

In situ means "in place," and refers to recovery techniques which apply heat or solvents to oil reservoirs beneath the earth. There are several varieties of in situ technique, but the ones that work best in the oil sands use heat.

The first in situ experiment in Alberta took place in 1910, when a Pittsburgh-based outfit, the Barber Asphalt and Paving Company, drilled a bore hole into the bitumen and pumped in steam to liquefy the oil. The experiment failed. In the early 1920s, other in situ experiments also took place, but none were commercially successful.

Jacob Owen Absher: In the mid-1920s, a remarkable and persistent experimenter named Jacob Owen Absher incorporated the Bituminous Sand Extraction Company. In 1926, Absher received a Canadian patent for his in situ experiments, and he carried on numerous experiments over the following five years - efforts that drew the interest of oil sands pioneers Sidney Ells and Karl Clark. Absher not only used steam to melt the bitumen, but also tried igniting fires within his wells. In the end, however, he was unable to produce oil from the oil sands. His activities ended as the Great Depression raged.

While Absher has been largely forgotten as a pioneer in the oil sands business, others have realized his dream of using heat to release oil from the sands. Today, some commercial projects pipe high-pressure steam into the oil sands reservoir. Other projects actually ignite the oil underground, then pump air below the surface to keep combustion going. These techniques effectively melt the oil, which pumps then bring to the surface.

Thermonuclear thinking: The most dramatic proposal for in situ production from deep oil sand deposits came from Richfield Oil Company. In 1959 Richfield suggested an experimental plan to release liquid hydrocarbons from the sand through the expedient of an underground nuclear explosion. The company proposed detonating a 9-kiloton explosive device below the oil sands at a site 100 kilometres south of Fort McMurray. Thermonuclear heat would create a large underground cavern and simultaneously liquefy the oil. The cavern could serve as a collection point for the now-fluid oil, enabling the company to produce it.

This idea came remarkably close to reality. The project received federal approval in Canada, and the United States Atomic Energy Commission agreed to provide the device. But before the experiment could take place, public pressure for an international ban on nuclear testing had mounted. The provincial government withheld approval and thus killed the plan.

In situ bitumen production: Many companies experimented with thermal techniques to produce heavy oil from the oilsands, especially in the Cold Lake oilsands deposit, in the 1970s and 1980s. Bearing such field-hand monikers as "steam flood", "fire flood" and "huff and puff" techniques, these extraction methods - like the Barber Asphalt and Paving Company's 1910 experiment - essentially apply heat to the underground reservoir. This melts the oil - that is, decreases its viscosity - so it can be pumped to the surface. An increasingly successful system now in use is steam assisted gravity drainage (SAGD).

SAGD was initially tested at the Underground Test Facility (UTF), ah experimental bitumen mining project funded by AOSTRA and officially opened on June 29th, 1987. The magnitude of the UTF is hard to imagine. Sinking the shafts was done with a drill bit almost four metres in diameter, weighing 230 tonnes. The two shafts below the oil sand reservoirs were 223 metres deep and neither one deviated from the vertical by more than 25 mm. As a safety measure, AOSTRA constructed two parallel tunnels through the limestone under the oil sand reservoir. More than a kilometre in length, each tunnel was five metres wide by four metres high.

From the tunnels the researchers drilled wells up into the reservoir to conduct two sets of tests. The Phase A pilot involved three well pairs 70 metres in length, each with 40-50 metres of exposure to the McMurray formation. Phase B involved another three well pairs, 70 metres apart, each with 500 to 550 metres of direct contact with the oil sand reservoir. The results were excellent, and the petroleum industry soon began producing bitumen through SAGD well pairs drilled and operated from the surface.

The largest single plant in Canada to use in situ production is Imperial Oil's Cold Lake oil sand plant. This plant uses a technique called cyclic steam injection. Using this method, the company pumps high-pressure steam into a section of the underground reservoir for a week or so, then pumps the liquid oil out for as long as several months. Imperial also uses steam-assisted gravity drainage. In its SAGD production system, Imperial drills two horizontal wells, one five metres above the other. Steam injected through the upper well reduces the viscosity of the oil, which is recovered through the lower borehole. This plant produces more than 150,000 barrels (24,000 m3) of bitumen per day.

The first Asian-owned company involved in the oil sands was JACOS, which in 1978 began participating in experiments at a pilot project in the Athabasca area. Like Imperial at Cold Lake, from 1984 to 1994 JACOS and its partners also experimented with a cyclic steam stimulation pilot project on the Hangingstone Lease. Since then the company has developed SAGD production on that lease. It is also constructing a demonstration plant using solvent-based in situ bitumen extraction.