Bituminous sands

In addition to conventional petroleum (qv) and heavy cmde oil, there remains another subclass of petroleum, one that offers to provide some rehef to potential shortfalls in the future supply of Hquid fuels and other products. This subclass is the bitumen found in tar sand deposits (1,2). Tar sands, also known as oil sands and bituminous sands, are sand deposits impregnated with dense, viscous petroleum. Tar sands are found throughout the world, often in the same geographical areas as conventional petroleum. 

In a general sense, however, the term heavy oil is often appHed to a petroleum that has a gravity <20° API. The term heavy oil has also been arbitrarily used to describe both the heavy oil that requires thermal stimulation for recovery from the reservoir and the bitumen in bituminous sand (also known as tar sand or oil sand) formations, from which the heavy bituminous material is recovered by a mining operation. Extra heavy oil is the subcategory of petroleum that occurs in the near-soHd state and is incapable of free flow under ambient conditions. The bitumen from tar sand deposits is often classified as an extra heavy oil. 

Tar sand, also variously called oil sand (in Canada) or bituminous sand, is the term commonly used to describe a sandstone reservoir that is impregnated with a heavy, viscous black extra heavy cmde oil, referred to as bitumen (or, incorrectly, as native asphalt). Tar sand is a mixture of sand, water, and bitumen, but many of the tar sand deposits in the United States lack the water layer that is beHeved to cover the Athabasca sand in Alberta, Canada, thereby faciHtating the hot-water recovery process from the latter deposit. The heavy asphaltic organic material has a high viscosity under reservoir conditions and caimot be retrieved through a weU by conventional production techniques. 

Tar sand has been defined as sand saturated with a highly viscous cmde hydrocarbon material not recoverable in its natural state through a well by ordinary production methods (2—8). Technically the material should perhaps be called bituminous sand rather than tar sand because the hydrocarbon is bitumen, ie, a carbon disulfide-soluble oil. 

The term tar sands is a misnomer tar is a product of coal processing. Oil sands is also a misnomer but equivalent to usage of "oil shale." Bituminous sands is more correct bitumen is a naturally occurring asphalt. Asphalt is a product of a refinery operation, usually made from a residuum. Residuum is the nonvolatile portion of petroleum and often further defined as atmospheric (bp > 350° C) or vacuum (bp > 565° C). For convenience, the terms "asphalt" and "bitumen" will be used interchangeably in this article. 

Bituminous sand a formation in which fhe bifuminous material (see Bitumen) is found as a filling in veins and fissures in fractnred rocks or impregnating relatively shallow sand, sandstone, and limestone strata a sandstone reservoir that is impregnated with a heavy, viscons black petroleumlike material that cannot be retrieved throngh a well by conventional production techniqnes. 

Statement 1. Bituminous sand is an aggregate of sand, clayey matter, oil and water. The sand consists mainly of quartz particles of 50 to 200-mesh size and smaller, but also of particles of other minerals including mica, rutile, ilmenite, tourmaline, zircon, spinel, garnet, pyrite, and lignite. Clay occurs interbedded with the bituminous sand itself. Ironstone nodules of all sizes up to eight inches in diameter occur in the bituminous sand beds, especially in the southern part of the deposit. The oil is viscous, naphthenic, and of a specific... 

Statement 6. Satisfactory separation of oil from sand by the hot water process is impossible unless the natural packing of the bituminous sand is completely broken down in the pulping operation and unless the pulp is subsequently dispersed in excess water. The mineral particles and oil flecks must be free to move independently of each other under the influence of the small forces upon which the process depends. 

Water wets quartz and other siliceous minerals more readily than does mineral oil. Consequently water tends to displace the oil films surrounding the quartz and other siliceous particles when the bituminous sand is mixed with water. Whether the oil is completely displaced depends on the properties of the water. That is to say, the materials dissolved or suspended in the water modify its wetting properties. 

When bituminous sand is mixed with water, substances present dissolve or become suspended in the water and determine its ability to displace the oil from the sand surfaces. This ability is a function of the concentration of substances dissolved in or suspended in the water. 

When bituminous sand is mixed with a small quantity of water, the concentration of substances which dissolve or are suspended in the water is greater than when a large quantity of water is used. The small quantity of water, after having been mixed with the bituminous sand, is a better wetting agent and displaces the oil from the sand more completely than is the case with a large quantity of water. 

When bituminous sand is mixed and heated with water into a mortar-like pulp, the oil is dispersed into small oil flecks which lie unattached among the sand grains. The content of clayey material in bituminous sand plays an important role in fleck formation and fleck formation plays an important role in the hot water separation process. In the rare cases of bituminous sands containing practically no clay, the separation process proceeds unsatisfactorily. 

The oil flecks present in a bituminous sand pulp vary in size and in the amount of clayey material that is associated with them. As the clay content of bituminous sand increases, the amount of clay associated with the oil flecks increases. 

Blair, S. M., Report on the Alberta Bituminous Sands, Government of... 

Tar sands is an expression commonly used in the petroleum industry to describe sandstone reservoirs impregnated with a very heavy viscous crude oil which cannot be produced through a well by conventional production techniques. Two other terms, bituminous sands and oil sands, are gaining favor. The heavy viscous petroleum substances impregnating the tar sands are called asphaltic oils. See also Tar Sands. 

The pentane extract from the Athabasca bituminous sand obtained from the quarry of Great Canadian Oils Sands, Ltd. 

Thus, alternative names, such as bituminous sand or oil sand, are gradually finding usage, with the former name (bituminous sands) more technically correct. The term oil sand is also used in the same way as the term tar sand, and these terms are used interchangeably throughout this text. 

Major deposits of tar sands, also called bituminous sands or oil sands, represent considerable hydrocarbon reserves (Table 17.4). The largest of these reserves-in-place occur in (Table 17.4) Canada in the Fort McMurray area of Alberta. While the reserves in place for these deposits are estimated to be of the order of 120 x 10 metric tonnes it is thought that only about one-quarter of this, or about 30 x 10 metric tonnes, is eventually recoverable... 

Tar sand the several rock types that contain an extremely viscous hydrocarbon that is not recoverable in its natural state by conventional oil well production methods including currently used enhanced recovery techniques see also Bituminous sand. 

More descriptively, tar sand is an unconsolidated-to-consolidated sandstone or a porous carbonate rock, impregnated with bitumen. In simple terms, an unconsolidated rock approximates the consistency of dry or moist sand, and a consolidated rock may approximate the consistency of set concrete. Alternative names, such as bituminous sand or (in Canada) oil sand, are gradually finding usage, with the former name more technically correct. The term oil sand is also used in the same way as the term tar sand, and the terms are used interchangeably. The term oil sand is analogous to the term oil shale. Neither material contains oil, but oil is produced therefrom by application of thermal decomposition methods. It is important to understand that tar sand and the bitumen contained therein are different components of the deposit. The recovery of the bitumen, a hydrocarbonaceous material that can be converted into synthetic crude oil (Speight, 1990,... 

Peterson, W. S., and P. E. Gishler, "A Small Fluidized Solids Pilot Plant for the Direct Distillation of Oil from Alberta Bituminous Sands," Canadian Journal of Research, 28 (January 1950) 62-70. 

Ward, S. H. Clark, K. A. Determination of the Viscosities and Specific Gravities of the Oils in Samples of Athabasca Bituminous Sand Research Council of Alberta Edmonton, Canada, 1950 Report No. 57. 

---