The rise of unconventional fossil fuel sources

Fossil fuels remain a dominant energy source globally, but as easily accessible reserves diminish, attention has turned to more challenging alternatives. In 2014, fossil fuels accounted for 81% of worldwide energy use. As traditional reserves deplete, their prices rise, making it economically worthwhile to pursue less accessible options.

What are unconventional fossil fuel sources?

Unconventional fossil fuel sources refer to reserves that are harder to access than conventional ones, often requiring advanced technology and higher costs. These include deposits trapped in difficult geological formations or remote locations. Energy companies are increasingly investing in methods to extract them, driven by the need to meet growing demand and maintain supply as conventional sources decline. This shift could also lead to exploration in sensitive areas, such as Antarctica, where reserves might be tapped despite environmental protections.

Main types of unconventional fossil fuel sources

There are four primary types of unconventional fossil fuel sources, each involving specialised extraction techniques. These methods allow access to resources that were previously uneconomical or technically unfeasible.

Key types and extraction methods

• Hydraulic fracturing (fracking) - This process extracts natural gas from shale rock. High-pressure fluid is injected into the rock to create cracks, releasing trapped gas that is then collected. It has been widely used in places like the USA, where over 1.7 million wells have been created.
• Tar sands extraction - Tar sands are sediments containing bitumen, a low-grade form of oil. The process involves mining the sediment and separating the oil through crushing and chemical treatment. It requires about two tonnes of tar sand to produce one barrel of oil, leading to large-scale operations, as seen in Canada.
• Oil shale processing - Oil shale is a rock that releases shale oil when heated and pressurised. This method converts the solid resource into usable liquid fuel.
• Deep water oil drilling - This targets oil reserves beneath the ocean floor in deep waters. Specialised rigs enable drilling at great depths, such as off the coast of Brazil.

These techniques expand energy supplies but often come with higher environmental and financial costs compared to conventional methods.

Costs and benefits of developing unconventional fossil fuels

Developing unconventional fossil fuels brings a mix of advantages and drawbacks, affecting economies, environments, and communities. Weighing these factors is essential for understanding their role in global energy strategies.

Overview of costs and benefits

These impacts highlight the trade-offs: while benefits often focus on economic gains, costs tend to emphasise environmental and health risks. As fossil fuels become scarcer, the pressure to exploit these sources grows, but so do concerns about long-term sustainability.

Case study: Canadian tar sands

Canada holds the world's largest tar sands reserves, particularly in the Athabasca region of Alberta, where mining has occurred since 1967. Extraction becomes viable only when oil prices are high due to the significant costs involved.

Environmental impacts

• Large volumes of water are used to separate oil from crushed sands, producing toxic wastewater that contaminates natural water courses.
• This wastewater kills aquatic life and prevents new vegetation from growing in affected areas.
• The ecologically sensitive landscape faces ongoing threats, with mining causing widespread habitat destruction.

Economic benefits

The industry provides substantial local income, directly or indirectly employing over 400,000 people.

Social consequences

Indigenous communities in Athabasca have been displaced, losing access to traditional hunting and fishing grounds. This disruption erodes cultural practices and severs connections to ancestral lands.

This case illustrates how economic gains from tar sands can conflict with environmental protection and social equity.

Case study: USA fracking

Fracking for shale gas has expanded rapidly in the USA since 2005, occurring in over 30 states, primarily Texas and Colorado. It targets dispersed gas pockets, requiring extensive site preparation.

Environmental and health concerns

• Habitat disruption - Clearing vegetation for drilling sites leads to habitat destruction, prompting wildlife migration and biodiversity loss.
• Wastewater issues - In 2014, Colorado fracking sites produced over 3 billion gallons of highly toxic wastewater, raising fears of contamination in drinking water sources.
• Air pollution - Methane and other gases released during operations increase local air pollution.

Impact on the energy mix

Shale gas has surpassed coal as the USA's primary energy source, reducing reliance on coal-fired power stations but introducing new pollution challenges. Fracking demonstrates how unconventional methods can transform energy mixes while sparking debates over environmental safety.

Case study: Brazilian deep water oil

Brazil's deep water oil exploration began with the Lapa oilfield in the Santos Basin, discovered in 2007 and operational from 2017. Located 270 km offshore at depths over 2 km, it represents a push into challenging marine environments.

Technical challenges

Drilling at such depths requires advanced platforms and longer pipelines to shore, increasing costs and passing higher prices to consumers.

Strategic importance

• Petrobras, Brazil's state-owned oil company, aims to boost production to diversify the energy mix.
• Currently, much of Brazil's electricity comes from hydroelectric power, but climate change-induced droughts could reduce river flows and power generation.
• This development seeks to reduce dependence on vulnerable renewables by incorporating more fossil fuel-based electricity.

This example shows how deep water oil addresses energy security but at elevated financial and technical risks.