Technology & Process
- Is hydraulic fracturing a new technology?
- What is multistage hydraulic fracturing?
- What happens when shallow hydraulic fracturing is carried out through or close to a coal seam?
- How does the industry reduce the chance of hydraulic fracturing migrating to an abandoned well or an overlying formation?
- Can hydraulic fracturing create earthquakes?
Is hydraulic fracturing a new technology?
Hydraulic fracturing is a safe, proven and government-regulated technology that has been used in Canada for more than 60 years. In Western Canada, over 175,000 wells have been stimulated using hydraulic fracturing.
Over the past six decades, hydraulic fracturing has become ever more sophisticated and safe. Petroleum service companies continue to invest in science and technology in order to constantly refine and evolve the practices involved in hydraulic fracturing.
Here are just a few examples of how PSAC member companies are applying science and technology to their hydraulic fracturing operations:
- Large, state-of-the-art hydraulic fracturing research and development centres and labs to ensure design and quality control are done a controlled environment
- Regional labs at field stations for rapid response during well completion operations
- Real-time microseismic fracturing monitoring and interpretation
- Hydraulic fracturing simulators to map out what will happen at the site
- Scientific protocols for evaluating and selecting hydraulic fracturing additives in locations with limited regulations
- Equipment designed to reduce the wellsite footprint and the number of loads on the road
- Environmentally friendly fluids chemistries and technologies that will allow fracturing with less water, proppant and chemicals, thereby reducing truck traffic and onsite storage space requirements
Hydraulic fracturing companies are committed to continuous improvement because they have to be. This sector of the industry – like many others – is highly competitive. If companies don’t strive to continually improve, they will be left behind.
But it’s not just competition that motivates hydraulic fracturing companies to be safer, more efficient and more environmentally friendly. If a company doesn’t perform at the highest level with each and every fracturing operation, they could risk the well, the local environment, the community and their reputation. Companies are simply not going to take that big of a risk.
What is multistage hydraulic fracturing?
Multistage hydraulic fracturing is most often done in horizontal wells. Horizontal wells now account for more than 70% of wells drilled.
Horizontal drilling allows greater access to the target reservoir without drilling multiple wells. A single well can have multiple legs, at different levels or in different directions. Or one well pad can be the source of multiple horizontal wells, efficiently located close together which really reduces the surface footprint.
Horizontal legs can be up to 3,500 metres long – it would take a person 45 minutes to walk that far! Horizontal drilling has enabled substantial growth in the oil and natural gas supply in North America, while reducing the total number of wells drilled.
In horizontal wells, hydraulic fracturing is done in multiple stages, starting at the end of the leg and working back to the vertical part of the well (see illustrations below). This is known as multistage hydraulic fracturing – a very significant development that has helped improve our control of the process and in essence made it much safer and easier to manage.
For more information, read these issues of PatchWorks:
What happens when shallow hydraulic fracturing is carried out through or close to a coal seam?
Coal formations are more easily fractured than shale zones. So when hydraulic fracturing takes place close to a coal seam, there is the potential to fracture into the coal seam. In such situations, some fracture fluid and proppant travel into the coal formation, leaving less fracture fluid in the main fracturing zone. This tends to reduce both the height and length of the fracture in the target zone.
How does the industry reduce the chance of hydraulic fracturing migrating to an abandoned well or an overlying formation?
Fractures in oil and gas bearing rocks extend along the path of least resistance.
Vertically, fractures extend until they reach a different type of rock formation, such as a softer shale, that’s more difficult to fracture. These rock layers contain the fractures vertically and cause them to travel horizontally within the more brittle layers of the targeted formation.
The most growth of fractures is in a horizontal direction. Fractures are contained horizontally when the pumping pressure is insufficient to continue fracturing the rock or when the fracture fluid disperses into the formation. Computer modelling is done prior to hydraulic fracturing to identify the specific parameters. The entire hydraulic fracturing process is monitored and controlled to ensure the fractures are limited to within the defined parameters.
Can hydraulic fracturing create earthquakes?
Seismic activity is associated with several industrial processes, including geothermal energy extraction, mining, dam building, construction and hydraulic fracturing in natural gas development. Seismic activity resulting from human activity is called induced seismicity.
The process of hydraulic fracturing occasionally sends vibrations from the fracturing zone to the surface. These vibrations can be detected and measured at the surface, but are normally too slight to be noticed by humans. Hydraulic fracturing-related seismic events usually result from the fracturing process releasing naturally built up tectonic stresses, which will eventually be released as a normal course of nature. Scientific evidence indicates that seismic activity resulting from hydraulic fracturing causes no injury or property damage, nor poses a risk to public safety or the environment. For more information, please visit:
In BC, industry is cooperating with the BC Oil and Gas Commission to monitor seismic activity in the Horn River Basin and ensure the continued safe development of shale gas in the area. For more information, please visit:
For more frequently asked questions about hydraulic fracturing, visit:
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