Fracking in Canada was first used in Alberta in 1953 to extract hydrocarbons from the giant Pembina oil field, the biggest conventional oil field in Alberta, which would have produced very little oil without fracturing. Since then, over 170,000 oil and gas wells have been fractured in Western Canada. Fracking is a process that stimulates natural gas or oil in wellbores to flow more easily by subjecting hydrocarbon reservoirs to pressure through the injection of fluids or gas at depth causing the rock to fracture or to widen existing cracks.
New hydrocarbon production areas have been opened as fracking stimulating techniques are coupled with more recent advances in horizontal drilling. Complex wells that are many hundreds or thousands of metres below ground are extended even further through drilling of horizontal or directional sections. Massive fracturing has been widely used in Alberta since the late 1970s to recover gas from low-permeability sandstones such as the Spirit River Formation. The productivity of wells in the Cardium, Duvernay, and Viking formations in Alberta, Bakken formation in Saskatchewan, Montney and Horn River formations in British Columbia would not be possible without fracking technology. Fracking has revitalized legacy oilfields. "Hydraulic fracturing of horizontal wells in unconventional shale, silt and tight sand reservoirs unlocks gas, oil and liquids production that until recently was not considered possible." Conventional oil production in Canada was on a decrease since about 2004 but this changed with the increased production from these formations using fracking. Fracking is one of the primary technologies employed to extract shale gas or tight gas from unconventional reservoirs.
In 2012 Canada averaged 356 active drilling rigs, coming in second to the United States with 1,919 active drilling rigs. The United States represents just below 60 percent of worldwide activity. New Brunswick, Newfoundland, Nova Scotia and Quebec have banned fracking.
Geological formations The Spirit River, Cardium, Duvernay, Viking, Montney (AB and BC), and Horn River formations are stratigraphical units of the Western Canadian Sedimentary Basin (WCSB) which underlies of Western Canada and which contains one of the world's largest reserves of petroleum and natural gas. The Montney Formation, located in Northeast British Columbia and West-Central Alberta, and the Duvernay Formation located in central Alberta, are currently the most prospective formations in the WCSB for development of unconventional oil and gas reservoirs that require hydraulic fracturing stimulations. The Bakken formation is a rock unit of the Williston Basin that extends into southern Saskatchewan. In the early 2000s significant increase in production the Williston Basin began because of application of horizontal drilling techniques, especially in the Bakken Formation.
Technologies
The first commercial application of hydraulic fracturing was by Halliburton Oil Well Cementing Company (Howco) in 1949 in Stephens County, Oklahoma and in Archer County, Texas, using a blend of crude oil and a proppant of screened river sand into existing wells with no horizontal drilling. In the 1950s about of fluid and were used. By 2010 treatments averaged "approximately of fluid and of propping agent, with the largest treatments exceeding of fluid and of proppant."
In 2011 the Wall Street Journal summarized the history of hydraulic fracturing,
Horizontal oil or gas wells were unusual until the 1980s. Then in the late 1980s, operators along the Texas Gulf Coast began completing thousands of oil wells by drilling horizontally in the Austin Chalk, and giving 'massive' hydraulic fracturing treatments to the wellbores. Horizontal wells proved much more effective than vertical wells in producing oil from the tight chalk. In the late 1990s in Texas, combining horizontal drilling and multi-stage hydraulic fracturing techniques made large-scale commercial shale gas production possible. Since then, shale gas wells have become longer and the number of stages per well has increased. As shale gas companies target deeper, hotter, more unstable reservoirs, drilling technologies have been developed to tackle challenges in various environments.
Drilling TechnologyDescriptionEnvironmentUnderbalanced drilling - Drilling fluid operated at pressure less than pore pressure
- Using compressed gas or foam
- Speeds up penetration rate, reduces drilling costs and formation damageDepleted zones, highly fractured and porous formationPercussion/hammer drilling- Repeated impact to break rock at drill bit;
- Drill bit contact with formation is 2% of operational time
- Less tool wear
- Impact and rebound can be self-sufficient and self-sustainedHard rock formationsRadial drilling - 50 to 100 meters long laterals from mother well;
- Controlled direction
- Increase drainage radius and flow profile near wellbores
- Rotary, jet-impact, plasma drilling methodsNear cap rock, water table, faults, and depleted zonesDrilling with liner/casing - Installing liner without extracting drilling assembly
- Prevents fracturing, closure and collapse of wellboreSwelling shales, creeping formations, high pressure zones, and depleted zonesMonodiameter drilling liner - Creates continuous diameter of casing using expandable tubular technology
- Decreases amount of drilling fluid and cement volumes, casing weight, and cutting disposalSame environment as conventional telescoping casing installationNon-invasive drilling fluids - Polymer, water, and oil mixture
- Polymer seal pore throats and fractures
- Prevents infiltration of fluid into formationDepleted zones, highly fractures and porous formationsReversible invert emulsion fluid - Can switch between water-in-oil and oil-in-water emulsion
- Water-in-oil fluid prevent fluid loss, washout, and swelling
- Oil-in-water offer better cleanup for better cementingSwelling shales, salt zones, highly fractured and porous formations
In parallel with the advancement in drilling technologies, injection technologies have also seen changes. Injection TechnologyDescriptionDrawbacksGas - Commonly use carbon dioxide and nitrogen;
- Does not plug pore throats
- Carbon dioxide replaces adsorbed natural gas in reservoir
- Faster flowback
- Avoids use of water
- Higher production if using carbon dioxide. - Low proppant carrying capacity
- High velocity proppant erodes equipment
- Pressurized containers for transport and storageLiquid carbon dioxide - Liquid at -34.5 °C and 1.4 MPa
- High proppant carrying capacity
- Turns to gas in reservoir
- Replaces adsorbed gas in reservoir
- Does not plug pore throats
- Fast flowback
- Avoids use of water
- Higher production. - Transport and storage of low temperature gas
- Potential greenhouse effectSupercritical Carbon dioxide(SC‐CO2) - Usually at depths greater than 1,000 m
- Not lower than (L‐CO2) temperatures.
- Viscosity of SC‐CO2 is much lower than normal L-CO2.
- SC‐CO2 breakdown pressure is lower than L-CO2 - Difficult to change to this liquid state
- Difficult to get this low temperature
- In this case depth and pressure also difficult to achieve Liquefied petroleum gas (LPG) - No waste production and environment friendly
- Almost 100% of propane gas is pumped back
- Only 50% of hydraulic frack fluid remains underground - Much more expensive than water - Potential risks to use in field work operation
- Transport and storage is a challengeHigh energy gas fracturing (HEGF) - To produce multiple radial fractures in formation
- Cheap operation
- Simple implementation
- Little pollution to formation - Not well suited in overcoming certain types of recurring damage mechanisms, such as salt depositionFoam - Liquid aerated, typically with N2
- Has wide range of viscosity based on foam ratio
- Less water usage
- Reduces swelling but cannot eliminate it
- Reduces water-locking - Reduces but cannot eliminate swelling and water-locking issuesImpulse sand fracturing - Effective and environmental friendly - Highly increase well production
- Decrease the volume of fracturing proppant
- Lower sand plugging risks
- High initial fluid rate - Expensive - Prolonged plugging operations
Cost and lifespan of hydraulic fracturing Oil producers spend US$12 million upfront to drill a well but it is so efficient and produces so well during its short, 18-month lifespan, that oil producers using this technology can still make a profit even with oil at $50 a barrel.
Lifespan of hydraulic fracturing:
The lifecycle of shale gas development can vary from a few years to decades and occurs in six major stages, as described by Natural Resources Canada (NRC), assuming all approvals from the various regulatory authorities have been obtained:
Stage One: Exploration, which involves applying for the appropriate licenses and permits, leasing the mineral rights, Indigenous consultations, community consultations and geophysical studies, including geological assessments and seismic surveys; Stage Two: Site preparation and well construction, which includes exploratory drilling to determine the physical and chemical characteristics of the rock and to assess the quality and quantity of the resource; Stage Three: Drilling, which includes horizontal drilling; Stage Four: Stimulation, which is the use of hydraulic fracturing to enable the hydrocarbons to flow to the wellbore; Stage Five: Well operation and production, which can operate for 10 to 30 years; and, Stage Six: End of production and reclamation, which requires the company to properly seal the well, clean and inspect the site. Reclamation occurs over several years as the company remediates any contamination, restores soil profiles, replants native vegetation and any other reclamation work required by local regulations.
Alberta
Because of its vast oil and gas resources, Alberta is the busiest province in terms of hydraulic fracturing. The first well to be fractured in Canada was the discovery well of the giant Pembina oil field in 1953 and since then over 170,000 wells have been fractured. The Pembina field is a "sweet spot" in the much larger Cardium Formation, and the formation is still growing in importance as multistage horizontal fracturing is increasingly used.
The Alberta Geological Survey evaluated the potential of new fracturing techniques to produce oil and gas from shale formations in the province, and found at least five prospects which show immediate promise: the Duvernay Formation, the Muskwa Formation, the Montney Formation, the Nordegg Member, and the basal Banff and Exshaw Formations. These formations may contain up to of gas-in-place.
Between 2012 and 2015, 243 horizontal multistage fractured wells were drilled in the Duvernay Formation producing of oil equivalent, distributed in of oil, of natural-gas condensate, and of natural gas. 201 of these wells were drilled in the Kaybob assessment area, whereas 36 wells, were drilled in the Edson-Willesden Green area and 6 wells in the Innisfail area, with horizontal lengths between 1000 and 2800 meters and well spacings between 150 and 450 meters. The development of condensate-rich areas in the Duvernay formation remain steady as the natural-gas condensate is a key product to dilute the bitumen produced from the closely located oil sands deposits in Athabasca, Peace River, and Cold Lake, and is traded with the same reference price as WTI oil.
Even as the price of oil declined dramatically in 2014, hydraulic fracturing in so-called "sweet spots" such as the Cardium and Duvernay in Alberta, remained financially viable.
British Columbia