Unconventional Energy Sources
According to oilfield services provider Schlumberger, unconventional resources is an umbrella term referring to oil and natural gas produced by means that do not meet the criteria for conventional production. Unconventional oil consists of a wider variety of liquid sources than conventional oil, including oil sands, extra heavy oil, gas-to-liquids and other liquids. In general conventional oil is easier and cheaper to produce than unconventional oil. However the qualification criteria for unconventional resources are not fixed and inevitably shift over time depending on the availability of exploration and production technologies, the economic environment and other factors. As of 2011 for example resources such as coal bed methane (CBM), shale gas, fractured reservoirs and tight gas sands are considered unconventional resources.
Many industry analysts have pointed to a significant future role for 'unconventionals' in the energy mix in many parts of the world. BP estimates that unconventional gas will account for 57% of US production by 2030, that CBM and shale will account for almost half of Chinese output growth, and that shale and other new gas sources could meet almost 60% of US supply needs by the same date. Nevertheless the IEA notes that further development of global unconventional energy resources requires a degree of social acceptance in order to flourish, due to the environmental and social concerns that have arisen.