There is a lot of talk about shale rock formations lately, especially as it pertains to drilling for oil and natural gas. What is so significant about shale and which types of drilling works best when it comes to extracting natural gas from this type of rock? 

What is Shale?

Shale is a type of sedimentary rock that is fine-grained and made when silt gets compacted with mud. It is also made up of many different layers that can split into thin pieces. Shale has sharp edges when it gets broken apart and comes in a variety of colors including: 

• Red
• Brown
• Green
• Gray
• Black

There are three types of sedimentary rocks including clastic, chemical, and organic. Shale falls under the clastic category which means it is a type of rock that is formed as a result of weathering processes.

What Do Shale and Natural Gas Have in Common?

There are certain places in both Canada and the United States where there are large formations of shale rock. While sedimentary rocks contain natural gas deposits, there is a reason it has taken years for oil companies to have the ability to extract this natural gas. One of those reasons is because shale has low permeability which means fluid does not flow through the rock easily.

When it comes to oil and natural gas extraction, there used to be only one method to do the job - vertical drilling. This type of drilling works extremely well for rocks that have high permeability but not so well for rocks with low permeability.

What Does Shale Have to Do with Directional Drilling?

Using advanced directional drilling methods such as horizontal drilling and hydraulic fracturing (fracking), has given oil companies the ability to extract oil from shale. These types of drilling methods allow the well bore to get closer to the shale so that even though this type of rock has low permeability, the oil can still get extracted. Because of the low permeability, this was simply not feasible with vertical drilling as the oil could not travel the long distance from the rock to the well.   

Canada ranks 5th in the world when it comes to natural gas production. Most of this natural gas is produced in Alberta and British Columbia, as well as the shores of Nova Scotia. There are also known shale rock formations located in many provinces including Ontario and Quebec. Using directional drilling techniques (click here for more info), there is the potential for Canada to produce more oil and natural gas than it has ever produced.