Since the 1920s, open pit mining has been central to oil sands development. But about 80% of the oil sands in Alberta are buried too deep for open pit mining. The oil must be recovered by in situ techniques. Steam is injected into the deposit to heat the oil sand, lowering the bitumen’s viscosity. The hot bitumen migrates toward producing wells, bringing it to the surface, while the sand is left in place (hence the name, in situ, which is Latin for “in place”). This technology is expensive, however, and requires certain conditions like a nearby water source. But, in situ production already rivals open pit mining and may well replace it as the main source of bitumen production.<\/p>\n