May 14, 2014, marks the 100th anniversary of the initial petroleum discovery at Turner Valley. The field sits at the leading edge of the Foothills Belt of the Rocky Mountains, just to the southwest of Calgary, Canada.
The field’s relatively simple structure features a massive thrust sheet carrying Mississippian carbonates at its base. The overlying Mesozoic section, deformed into a broad anticline, forms the crest of the Triangle Zone at this latitude and is related to the cut-out of the carbonates above the sole fault.
Understanding of the subsurface was incomplete during much of the life of the field and multiple visualizations of its geometry were proposed.
It was only after modern seismic techniques were brought to bear to complement the extensive drilling record that the true nature of the structure became apparent.
Turner Valley was not western Canada’s first discovery:
- Natural gas had been found at Langevin Siding in southeast Alberta in 1883, by railroad workers seeking water for their steam engines.
- The first decade of the 20th century had seen a flurry of activity in what is now Waterton National Park, adjacent to Glacier National Park, in fractured Precambrian clastics carried in the overthrust belt.
The combination of these small discoveries and the widespread feeling that having local oil discoveries was the key to prosperity set the stage for the excitement at Turner Valley.
In the Beginning
Early exploration at Turner Valley was triggered by surface seeps of natural gas – and by an understanding of the anticlinal theory of hydrocarbon accumulation.
W.S. “Stewart” Herron, a local rancher who had gained some experience in the Pennsylvania oilfields prior to coming west, recognized the opportunity for a local strike and had validated the deep source of the gas by sending samples to labs in California and Pennsylvania.
Herron proceeded to accumulate a sizeable land base. He promoted the opportunity to local businessmen who formed a company called Calgary Petroleum Products Limited to fund the drilling of a test well that was spudded on Jan. 25, 1913.
The rig was a California-type cable tool outfit rigged with an 85-foot wooden derrick. The boiler was coal-fired when the well spudded, but gas-fired after the first gas flow was encountered at a depth of 180 feet.
The consortium included businessman and driller A.W. Dingman, after whom these early wells are commonly named. Dingman, originally from Prince Edward Island, also had gained some field experience in Pennsylvania.
Speculation erupted following every show of oil or gas encountered in the wellbore, and speculators had a heyday. It is said that more than 500 new oil companies were formed during this exciting period.
Local humorist Bob Edwards quipped in his “Calgary Eye Opener” column, “The trouble with this oil situation at this formative stage is that you are never sure whether the man you meet on the street is a multi-millionaire, or just an ordinary, common millionaire.”
‘Hell’s Half Acre’
The discovery well, Calgary Petroleum Products No. 1, finally came in on May 14, 1914, at 4 mmcf/d of wet natural gas at a depth of 2,717 feet in the sandstones of the Lower Cretaceous section.
A small absorption plant was built to extract the natural gas liquids.
Unfortunately production did not live up to expectations, and development of the discovery was slow and hampered by the onset of World War I, which restricted the availability of capital.
And as to the speculation, it was written by Canadian petroleum historian Earle Gray:
“Within a few months Calgarians woke up from that monumental speculative spree with such a hangover that more than a half a century later the city still remembered the event as the wildest boom that ever hit the west.
“More than 500 companies had been formed within a few months, holding half a million acres of oil leases and with authorized capital totalling an estimated $400 million. Less than 50 companies actually started drilling, and few of those found any oil.
“Calgarians, wiped clean of more than a million dollars of savings, were left holding thousands of share certificates worth less than wallpaper. Several homes, and the lobby of one hotel, were actually wallpapered with share certificates.”
On Oct. 14, 1924, Royalite No. 4, drilled by a subsidiary of Imperial Oil that had taken over CPPL’s operations following a fire in 1921, deepened a northern step-out well into the underlying Paleozoic section and intersected the deep natural gas accumulation hosted in the Mississippian strata in the up-dip part of thrust sheet.
The well blew out and is estimated to have flowed at over 20 mmcf/d with 500-600 bbl/d of condensate. This pool is now recognized as having had 1.5 TCF OGIP.
Its pursuit occupied the industry from 1924 through to 1936. Exploitation primarily involved production of the natural gas for its condensate content. Sales of the residual gas were made when possible, but significant volumes often were flared when production exceeded demand – and gave the name “Hell’s Half Acre” to the gully in which this incineration was continually in progress.
Almost 160 bcf or over 400 mmcf/d of gas was flared in 1931.
The next chapter of the field’s life was ushered in by the testing on June 16, 1936, of Turner Valley Royalties No. 1, a downdip crude oil discovery in the Mississippian that came in at 850 bbl/d of 39-degree crude oil.
This deeper flank pool had one billion barrels OOIP and 1.36 TCF of solution gas, but recoverable oil volumes of only 156 mmbbl, due to the depressuring of the field during aggressive production of the associated gas cap.
A significant northern step-out in 1938 into the Millarville segment virtually doubled the strike length of the field. Oil production peaked at about 27,000 bbl/d in 1942, at which point the field was providing approximately 97 percent of Canada’s domestic production.
The intense development activity led to an influx of workers who established towns known as Little New York (now Longview) and Little Chicago (officially called Royalties, but now gone and only acknowledged with a small cairn).
Turner Valley has continued to attract industry attention even in the waning years of its primary pools:
- Unitizations accompanied by major water flood schemes were instituted in the late 1950s.
- Improved seismic resolution led to the identification of several additional hitherto untapped thrust imbricates in the field.
- There was a period of renewed interest in the Cretaceous section.
- More recently, the applications of horizontal wells and tertiary recovery processes have led to a modest revival of production, to about 7,000 bbl/d.
It is interesting to note the connection between the work of American geologists and Turner Valley. Early stratigraphic nomenclature was imported from south of the border, including:
- The Benton Shale, or Colorado Group (now Alberta Group), for the Late Cretaceous shale package.
- The Dakota and Kootenai formations (now Mannville and Blairmore groups) for the Early Cretaceous clastic-dominated section.
- The Madison Group (now Rundle Group, including the Turner Valley Formation) for the upper part of the Mississippian section.
A Historical Setting
The history of Turner Valley is rich in cultural and technological detail. Although relatively small by global standards, it brought significant economic activity, employment and financial rewards to individuals, companies and governments.
The field also was important in other ways because of the timing of its life relative to global events.
First, its exploration and production occurred in part during the Great Depression, and therefore brought much needed relief to southern Alberta.
Then during World War II, crude oil production from Turner Valley was critical in the establishment and capacity of the British Commonwealth Air Training Program that was vital to the Allied war efforts.
Finally, as the home of the first full-scale commercial petroleum production facilities in Alberta, it positioned both the industry and the government for the rapid pursuit, beginning in 1947, of Leduc and other world-class discoveries in the Western Canada Sedimentary Basin.
Human, physical and capital resources were quickly redeployed from Turner Valley in the declining years of its life. Likewise, Alberta’s regulatory regime for the industry became firmly established in 1938 in recognition of the fact that conservation measures were required to combat wasteful approaches, so as to achieve optimal recovery efficiencies of subsurface resources – a need reinforced by the 1936 crude oil discovery.
Turner Valley was the early stomping ground for many individuals who went on to greater fame later in life:
♦ Ted Link, who was AAPG president 1956-57, was chief geologist for imperial Oil and published a synthesis on the field, together with P.D. Moore, in the AAPG BULLETIN in 1934. Link also was instrumental in the Imperial Oil discoveries at Norman Wells (1920) and Leduc (1947).
♦ Stanley Slipper, who was one of the first geologists to study the field, became the first president of the Alberta (now Canadian) Society of Petroleum Geologists in 1927, in the aftermath of the activity generated by the 1924 natural gas discovery.
♦ R.B. Bennett, one of the investors in CPPL, became prime minister of Canada between 1930 and 1935.
But it also is important to examine Turner Valley in its broader societal context as well; in 1912 there was so little petroleum in western Canada that the city of Calgary could not afford to purchase oil to keep down the dust on its streets. As a result, the 1914 discovery of the first commercial accumulation in the West bearing liquid hydrocarbons changed Alberta forever.
What’s in store for Turner Valley?
Is the field played out?
And there are still some significant technical puzzles. For example, why does Turner Valley contain the only significant crude oil accumulation in the Foothills Belt in this region?
Might a story about charge, retention and leakage lead the way to additional, as yet undiscovered pools?
Only time will tell.