Canada's oil and gas giant EnCana announced Sunday it was splitting in two separate entities: a natural gas company and "a fully integrated oil company." EnCana said one company, tentatively called IntegratedOilCo (IOCo), will focus on the development of EnCana's Canadian oilsands assets and natural gas and oil production base in Alberta and Saskatchewan, and refinery interests in the United States. In processing oilsands, natural gas is used to produce vapor which is injected into the ground to release the trapped oil in the sand.  Encana and ConocoPhillips jointly exploit the oilsands sites at Foster Creek and Christina Lake, which hold potential reserves of more than 6.5 billion barrels of oil. The group also controls the Borealis site with a 2.5 million barrel potential.