Unconventional Resource Technology
Unconventional resources are trapped in rock with limited or no flow pathways and are difficult to produce by simply drilling a well. Therefore, they require methods to “crack” or “fracture” the rock to allow oil and gas to flow up through the well.
Advancements in technology have allowed industry to develop unconventional resources. Currently, horizontal drilling, multiple wells from a pad and hydraulic fracturing are the three main methods and they are often used together to develop unconventional resources.
- Horizontal Drilling –uses a steerable drill-bit to drill a well along a horizontal path to better reach and obtain production from oil and gas reserves. Horizontal drilling has been around for decades but only recently has it been paired with multi-stage hydraulic fracturing. Today, more than half of western Canada’s oil and natural gas wells are being drilled horizontally, and since 2013, an estimated 80 per cent of all oil wells placed on production in Alberta utilized horizontal drilling techniques. The Government of Alberta, through the Alberta Energy Regulator (AER)'s statistical reports section, provides regular updates on drilling activity, well licenses, reserve calculations and economic outlook for Alberta’s resources.
Horizontal drilling techniques have the advantage of being able to increase resource recovery while reducing surface impacts. One horizontal well can access and drain resources that would require several vertical wells. A horizontal well offers considerable flexibility in the choice of a location for a natural gas or oil operational site. Multiple wells from a pad further help reduce surface impacts with less roads and pipelines required. Early landowner engagement is required when multiple industrial activities are planned.
Multiple wells from a pad
Drilling multiple wells from a pad entails drilling multiple wellbores, or drill holes, from a single surface location. The AER offers an illustration of different well types.
- Hydraulic Fracturing
(sometimes referred to by the non-technical term “fracking”) involves pumping fluids, typically water, into a formation at a high enough pressure to crack, or fracture, the rock layer. The fluid also contains proppant, such as sand, that helps keep the fractures open so that oil and gas can flow to the surface. Instead of water, some fracture operations use liquefied propane, nitrogen, liquefied carbon dioxide, diesel or other fluids.
There are two types of hydraulic fracturing:
- Single stage hydraulic fracturing
A single stage fracturing treatment which involves the use of one stage of fracturing in the wellbore.
- Multistage hydraulic fracturing
A multistage fracturing treatment which involves the use of more than one stage of fracturing in the wellbore. It combines the well-established techniques of horizontal drilling and high-pressure hydraulic fracturing at multiple intervals along the horizontal portion of the well. Multistage fracturing is a relatively new technology that has opened up resources that were previously inaccessible in Alberta.
- Single stage hydraulic fracturing
Hydraulic fracturing has been safely used in Alberta on more than 180,000 wells since the technology was introduced in the 1950s. Since 2008, more than 10,000 wells have been drilled in Alberta using the combination of multistage hydraulic fracturing and horizontal well drilling for oil and gas development. The AER requires all companies to disclose information on fluids used in hydraulic fracturing operations. This information is publicly available at FracFocus website. The Government of Alberta provides accurate and timely data and information to help explain and provide context around unconventional resource development in Alberta, particularly as relates to use of horizontal drilling and hydraulic fracturing in Alberta. Additional information can be found with Hydraulic Fracturing (Environment and Parks) or view the AER video on Drilling and Hydraulic Fracturing