What is Tight Oil?
Tight oil is crude oil trapped within tight geologic formations with low permeability and low porosity. Permeability is the ability of a fluid to flow through rock and porosity is the ability of that rock to hold fluid. Because of these unique geologic conditions, tight oil requires advanced drilling techniques such as horizontal drilling or hydraulic fracturing to be recovered.
There is some confusion over tight oil terminology due to the term “shale gas” being used to describe natural gas in tight formations. This is not equivalent for oil; the term “shale oil” or “oil shale” is not a type of tight oil. While in a similar geologic formation, it is a formation containing kerogen and requires different production techniques.
Since its discovery, hydraulic fracturing, or fracking, has become a main driver in the exploitation of tight oil resources. Advances in this technology have led to a new global energy landscape as it has allowed for large increases in production of petroleum in the United States, traditionally one of the world’s largest energy importers.
The development of fracking has been controversial due to environmental concerns. The process typically requires 11 million litres of water per well but can vary greatly depending on the characteristics of the geologic formation. Other environmental concerns include contamination of ground water, depletion of fresh water, and surface pollution in the drilling process. There are also concerns linking fracking to enhanced seismic activity.