OILPATCH PIONEERS

The Made-In-Canada Success of the Oilsands Owes a Great Debt to the Work of Researchers Karl Clark and Roger Butler

By Maurice Smith

(from New Technology Magazine, 10th Anniversary Edition)

TINY GRAINS OF SAND, SURROUNDED BY A THIN COATING OF WATER, encased in a tar-like deposit of crude oil — it doesn’t sound like much, but it’s a substance that has enthralled generations of researchers intent on cracking open its secrets. Of the dozens of scientists and entrepreneurs who have investigated the prospects of producing oil from the vast oilsands deposits of northern Alberta, two stand out as widely recognized luminaries of the present day industry: Karl Adolf Clark, whose hot water separation process opened up for production the 10% of oilsands deposits that lie close enough to the surface to be open pit mined; and Roger Moore Butler, whose thermal in-situ process opened the door to feasible extraction of reserves out of reach of surface producers.

Their careers bookmark much of the history of the oilsands industry, which has gone from a pipe dream to a mammoth business that has put Alberta on the world oil map. Working early in the 20th century, Clark doggedly pursued a commercially viable separation method during most of his career at the Alberta Research Council and the University of Alberta. He would see his ideas bear fruit shortly before his death in 1966, as Great Canadian Oil Sands (now Suncor Energy Inc.) completed the world’s first large-scale bitumen production facility to launch, along with Syncrude Canada Ltd. 11 years later, the first phase of surface oilsands production.

“That technology and the basis for the technology of hot water extraction is really what allowed the industry to move ahead,” says Phil Murray, ARC vice-president, Energy. “Although there have been many, many advances in technologies, it’s still the basis for what’s being used today.”

Butler would also see his steam-assisted gravity drainage (SAGD) concept commercialized before his death in May of this year, opening the second, in-situ, phase of Athabasca oilsands production. EnCana Corporation, Canadian Natural Resources Limited, Petro-Canada, Japan Canada Oil Sands Limited (JACOS), Husky Energy Inc. and Suncor (at Firebag) are among those now producing with SAGD technology, while many more projects are in the planning or construction phases.

Due to the research and perseverance of people like Clark and Butler, some 175 billion barrels of otherwise valueless oilsands have become widely acknowledged to be economically recoverable.

A second-generation Canadian with a doctorate in chemistry from the University of Illinois, Clark was introduced to the oilsands after taking a position with the Geological Survey of Canada and being transferred to its Mines Branch’s road material division. He initially promoted the oilsands as a road paving material. Paving trials were conducted in Edmonton and other Alberta cities, and a test strip was even laid on Wellington Street and Parliament Hill in Ottawa. But Clark quickly came to the conclusion that while paving could bide time while other uses were studied, the real potential lay in separating the bitumen from the sand.

As early as 1920 Clark was experimenting with samples of tar sands. He was not alone. A body of knowledge had already formed around separation techniques as a result of much smaller deposits of tar sands found in the U.S. and elsewhere. In fact, it was another Canadian scientist who was already leading research into Alberta’s oilsands that introduced Clark to early work in separation technology.

Sidney Ells, an engineer with the federal Department of Mines, was dispatched to characterize the oilsands in 1913. Ells was among the first to correctly grasp that the oilsands were not fed by an underlying pool of oil, as was earlier believed by those conducting drilling to prove that point. Like Clark, Ells was an early backer of oilsands use as a road paving material before becoming convinced that was not economically viable. He then became a life-long proponent of developing the oilsands, believing their greatest value lay in extracting the oil, and actively encouraged private sector involvement in their development. He toured several U.S. facilities where hot water separation had been attempted and for a time conducted further research at the Mellon Institute of Industrial Research in Pittsburgh, Pennsylvania.

Clark’s first assignment was to review Ells’s work regarding commercial development of the bituminous sands of Alberta. Then, while undertaking his own study of its potential for road paving, he unexpectedly created separation while working with standard emulsion procedures. His growing interest in the oilsands coincided with the creation of the Alberta Research Council (ARC) in 1921 and he was recruited as the ARC’s first researcher by Henry Marshall Tory, ARC’s founder and University of Alberta president. He would remain with ARC and the university for the balance of his career, a career renowned not so much for inventing the hot water separation method but for improving it and taking it to a commercially viable conclusion.

Clark, with assistant Sidney Blair, designed and built his own oilsands separation apparatus in the basement of the university’s power plant building in 1922. Incorporating his improvements on the standard process — which involved adding hot water to cause the quartz sand to sink to the bottom and the bitumen to float to the surface where it could be skimmed off — Clark created a relatively uncomplicated but effective technique. “To put it in layman terms, his initial processes weren’t completely dissimilar from an old hand-washing machine,” says Murray, noting the original has been put on display in ARC’s Edmonton office. The apparatus, which could treat half a ton of sand per hour for short periods, worked well enough to initiate construction of a larger, continuous separation facility at Dunvegan outside Edmonton in 1924.

Laboratory study of drying and cleaning operations continued and in 1929 the separation process became the subject of the ARC’s first patent, a patent that would be incorporated into the Suncor and Syncrude plants decades later. Essentially, it involved feeding the oilsands into a large rotating drum with a hot water-caustic soda mix. Aerating the slurry caused a floating froth of bitumen to form at the top which could be removed for further processing. The same year, the Dunvegan facility was dismantled for shipment north to the Fort McMurray area for pilot testing. It would process 730 tonnes of oilsands and produce 60,000 litres of bitumen in 1930.

On site piloting, and the chance location of the pilot in an area with an unusually high concentration of salts, led to a significant advance in the understanding of the process. High concentrations of iron salts caused high acidity. It was determined that separation worked best after the acid was neutralized, but that neutralizing with lime impeded separation. Neutralizing with soda ash before a hot water wash, however, led to a high level of separation.

Clark continued to spearhead improvements to the process both in the lab and in various experimental facilities. He produced numerous papers and reports while he taught in and later headed the University of Alberta’s Mining and Metallurgy Department. He acquired a second patent in 1948 dealing in part with the optimization of air bubbles in the separation process. His work led to the completion of a separation facility at Bitumount in 1949, since declared an Alberta Historic Site, that demonstrated the feasibility of the process. After his retirement, Clark consulted for Great Canadian Oil Sands until his death in 1966 at 78.

With the surface production of bitumen proven to be economic, it was left to researchers like Roger Butler to find a way to access the 90% of oilsands too deep for open pit mining. Born in England, Butler earned his PhD in chemical engineering at London’s Imperial College of Science and Technology in 1951. He taught at Queen’s University in Kingston, Ontario, before joining Imperial Oil Limited in 1955.

Imperial was a pioneer in in-situ thermal oil extraction, having developed cyclic steam stimulation (CSS) to extract bitumen from its vast Cold Lake oilsands leases. Commercialized in 1985 after several years of field testing, CSS, or “huff and puff,” involves a period of pumping steam downhole to a target formation, a period of soaking to lessen oil viscosity, and a period of producing.

Looking to improve upon a process that had limited application, Butler turned to a technique used in potash mining whereby water is pumped downhole to dissolve the potash and salt, producing a chamber in which the brine collects below the lighter water. Similarly, he reasoned, a steam chamber could be produced in a bitumen deposit, causing the heated bitumen to drain to the bottom. Extraction of the mobilized bitumen could then be continuous rather than in six- to 18-month cycles as experienced with CSS.

But his meticulous modelling of the technique based on the vertical drilling technology of the day indicated dismal levels of production. It was only when Butler adapted the concept to new horizontal drilling techniques coming onstream in the 1970s that production rates looked promising.

In 1978, Butler convinced Imperial to test the technique, which generally involves the drilling of parallel horizontal wells, one above the other, to inject steam from above and produce the mobilized bitumen from below. Already wedded to the CSS process it had developed, a technique particularly well suited to the Cold Lake deposits, Imperial took the process no further and Butler left the company to take the position of director of technical programs at the Alberta Oil Sands Technology and Research Authority (AOSTRA).

AOSTRA took the concept and ran with it, fine-tuning the technique with extensive testing conducted at its Underground Test Facility (UTF) in the Athabasca oilsands near Fort McMurray, though not before Butler had moved on to an appointment at the University of Calgary. AOSTRA’s work, which included development of computer simulations to optimize SAGD operations, and improved drilling techniques that allowed for precise placement of extended-length horizontal wells, contributed to the commercialization of the technology.

As Endowed Chair in Petroleum Engineering from 1983 to 1995, Butler not only continued to advance the SAGD concept, but originated a variation on the technique, the vapour extraction process (Vapex). Using a solvent rather than steam to mobilize the bitumen, Vapex holds considerable promise as a technique to significantly reduce energy use and emissions while partially upgrading bitumen in the reservoir.

Butler authored or co-authored more than 100 scientific papers and patents and wrote two books. After retirement from the university he founded a research and consulting company, GravDrain Inc., for the heavy oil industry.

It would be difficult to overestimate the impact of the work led by Clark and Butler in giving rise to today’s oilsands industry, says Eddy Isaacs, managing director of the Alberta Energy Research Institute. Isaacs, who was responsible for ARC’s programs in heavy oil and oilsands for more than 20 years, says SAGD represents a unique made-in-Canada solution to oilsands extraction after techniques imported from elsewhere proved ineffective. SAGD’s development is a perfect example of industry-government collaboration in bringing new technologies to market to boost energy production, he says, and Butler is recognized as its primary architect.

“Roger was a key to SAGD technology, there is no doubt about it, and to Vapex as well. He developed the models that show how fast these chambers grow, what oil rates you should expect and so on, and those are key to the economics — to determining how fast you get your oil back after you have invested,” says Isaacs. “Also, he and his students were very instrumental in evaluating the UTF work.”

Isaacs notes that independent estimates suggest SAGD makes available enough added reserves to support 340 independent projects producing 25,000 barrels of oil per day for 60 years.

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