Final answer:
Unconventional oil requires more energy than conventional oil due to the more complex and energy-intensive extraction methods like fracking and processing of tar sands.
Step-by-step explanation:
When comparing the energy requirements for extracting conventional and unconventional oil, unconventional oil generally requires more energy. Conventional oil extraction typically involves drilling into porous rocks and utilizing natural pressures or simple pumping techniques. In contrast, unconventional oil extraction relies on more complex and energy-intensive methods, such as hydraulic fracturing (fracking) and processing of tar sands. Fracking involves injecting high-pressure fluids to fracture the rock and release the oil or gas, whereas tar sands must be mined and processed, which involves significant energy expenditure. These methods are employed when more easily accessible conventional oil has been depleted, making unconventional sources increasingly more common.
Additional complications such as the need for horizontal drilling, water injection, and deep offshore drilling rigs for both types of oil can also increase the energy requirements. Problems like environmental impact, water contamination, air pollution, and the potential for earthquakes further complicate the use of unconventional oil extraction techniques.