Shale Oil and Gas: Current Status, Future, and Challenges

One of the most important foundations of the modern economy is energy. Despite significant investments and innovations in green energies (e.g., solar and wind) in recent years, still fossil fuels like crude oil, natural gas, and coal constitute the majority of the world's energy (80% energy from: oil [36%], coal [23%] and gas [21%] based on BP Statistical Review, 2012). Over the past decades, the nuclear and hydropower sources have increased their contribution to provide energy as well. Oil is mainly utilized for transportation and petrochemicals, coal for hydropower, nuclear for generating electricity, and gas mostly for heating purposes. Hence, the energy in the world is still considerably dependent on fossil fuel energies.