Energy

Bituminous sand

The terms bituminous sand, tar sand and oil sand refer to sand deposits that are not cemented together, and are very porous, and contain non mobile viscous oils. The largest known accumulation is in the region of Alberta (Canada), with an accumulation of oil that is over 60 m thick, at depths ranging from 0 to 600 m, in porous sand. The oil that is produced has a high content of sulphur and a very high viscosity level (2 x10⁶ cP). The tar sand of the surface deposits at Athabasca (one of the extraction sites in Alberta) have reserves amounting to 75-100 Gbbl. These have been exploited since 1963 with various active mines, and can produce 2.5 Mbbl per day, for 100 years (current production is 600,000 bbl a day). The largest reserves in tar sand are, in fact, in Canada (State of Alberta: Athabasca, Cold Lake, Peace River), in the Orinoco river basin in Venezuela and in Russia (The Siberian platform, Melekess). Other important deposits in tar sand are in China, India, Indonesia, Brazil and Ecuador. It is estimated that tar sand can contain reserves amounting to 5,000 Gbbl (billion barrels). Even if we consider that, at present, only 15-20% of these hydrocarbons can be extracted, these are however considerable amounts; for example, the Middle East has “conventional” reserves that are estimated to be 2,000 Gbbl, of which only 683 are considered extractable with the conventional methods.