18
The Chemistry and Technology of Petroleum
destructive distillation of such organic substances as coal (Speight, 1994). In the simplest sense,
pitch is the distillation residue of the various types of tar.
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.
However, in order to define bitumen, heavy oil, and conventional petroleum, the use of a single
physical parameter such as viscosity is not sufficient. Physical properties such as API gravity, elemental analysis, and composition fall short of giving an adequate definition. It is the properties of the bulk
deposit and, most of all, the necessary recovery methods that form the basis of the definition of these
materials. Only then is it possible to classify petroleum, heavy oil, and tar sand bitumen (Chapter 2).
1.4.7 WAx
Naturally occurring wax, often referred to as mineral wax, occurs as a yellow to dark brown solid
substance that is composed largely of paraffins (Wollrab and Streibl, 1969). Fusion points vary
from 60°C (140°F) to as high as 95°C (203°F). They are usually found associated with considerable
mineral matter, as a filling in veins and fissures or as an interstitial material in porous rocks. The
similarity in character of these native products is substantiated by the fact that, with minor exceptions where local names have prevailed, the original term ozokerite (ozocerite) has served without
notable ambiguity for mineral wax deposits (Gruse and Stevens, 1960).
Ozokerite (ozocerite), from the Greek meaning odoriferous wax, is a naturally occurring hydrocarbon material composed chiefly of solid paraffins and cycloparaffins (i.e., hydrocarbons) (Wollrab
and Streibl, 1969). Ozocerite usually occurs as stringers and veins that fill rock fractures in tectonically disturbed areas. It is predominantly paraffinic material (containing up to 90% nonaromatic
hydrocarbons) with a high content (40%–50%) of normal or slightly branched paraffins as well as
cyclic paraffin derivatives. Ozocerite contains approximately 85% carbon, 14% hydrogen, and 0.3%
each of sulfur and nitrogen and is, therefore, predominantly a mixture of pure hydrocarbons; any
nonhydrocarbon constituents are in the minority.
Ozocerite is soluble in solvents that are commonly employed for dissolution of petroleum derivatives, for example, toluene, benzene, carbon disulfide, chloroform, and ethyl ether.
In the present context, note that the term migrabitumen signifies secondary bitumen (secondary
macerals) generated from fossil organic material during diagenesis and catagenesis (Chapter 3). These
materials are usually amorphous solids and can be classified into several subgroups (Chapter 3).
1.4.8 AsPHAltIte And AsPHAltoId
Asphaltites are a variety of naturally occurring, dark brown to black, solid, nonvolatile bituminous
substances that are differentiated from bitumen primarily by their high content of material insoluble
in the common organic solvents and high yields of thermal coke (Yurum and Ekinci, 1995). The
resultant high temperature of fusion (approximate range 115°C–330°C, 240°C–625°F) is characteristic. The names applied to the two rather distinct types included in this group are now accepted and
used for the most part without ambiguity.
Gilsonite was originally known as uintaite from its discovery in the Uinta Basin of western
Colorado and eastern Utah. It is characterized by a bright luster and a carbon residue in the range
10%–20% by weight. The mineral occurs in nearly vertical veins varying from about an inch to
many feet in width and is relatively free of occluded inorganic matter. Samples taken from different veins and across the larger veins may vary somewhat in softening point, solubility characteristics, sulfur content, and so on, but the variation is not great. It is evident in all instances that it is
essentially the same material, and it is therefore appropriate to apply a single name to this mineral.
However, caution should be exercised in using the same term without qualification for similar materials until it can be shown that they are equivalent to gilsonite.
The Chemistry and Technology of Petroleum
destructive distillation of such organic substances as coal (Speight, 1994). In the simplest sense,
pitch is the distillation residue of the various types of tar.
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.
However, in order to define bitumen, heavy oil, and conventional petroleum, the use of a single
physical parameter such as viscosity is not sufficient. Physical properties such as API gravity, elemental analysis, and composition fall short of giving an adequate definition. It is the properties of the bulk
deposit and, most of all, the necessary recovery methods that form the basis of the definition of these
materials. Only then is it possible to classify petroleum, heavy oil, and tar sand bitumen (Chapter 2).
1.4.7 WAx
Naturally occurring wax, often referred to as mineral wax, occurs as a yellow to dark brown solid
substance that is composed largely of paraffins (Wollrab and Streibl, 1969). Fusion points vary
from 60°C (140°F) to as high as 95°C (203°F). They are usually found associated with considerable
mineral matter, as a filling in veins and fissures or as an interstitial material in porous rocks. The
similarity in character of these native products is substantiated by the fact that, with minor exceptions where local names have prevailed, the original term ozokerite (ozocerite) has served without
notable ambiguity for mineral wax deposits (Gruse and Stevens, 1960).
Ozokerite (ozocerite), from the Greek meaning odoriferous wax, is a naturally occurring hydrocarbon material composed chiefly of solid paraffins and cycloparaffins (i.e., hydrocarbons) (Wollrab
and Streibl, 1969). Ozocerite usually occurs as stringers and veins that fill rock fractures in tectonically disturbed areas. It is predominantly paraffinic material (containing up to 90% nonaromatic
hydrocarbons) with a high content (40%–50%) of normal or slightly branched paraffins as well as
cyclic paraffin derivatives. Ozocerite contains approximately 85% carbon, 14% hydrogen, and 0.3%
each of sulfur and nitrogen and is, therefore, predominantly a mixture of pure hydrocarbons; any
nonhydrocarbon constituents are in the minority.
Ozocerite is soluble in solvents that are commonly employed for dissolution of petroleum derivatives, for example, toluene, benzene, carbon disulfide, chloroform, and ethyl ether.
In the present context, note that the term migrabitumen signifies secondary bitumen (secondary
macerals) generated from fossil organic material during diagenesis and catagenesis (Chapter 3). These
materials are usually amorphous solids and can be classified into several subgroups (Chapter 3).
1.4.8 AsPHAltIte And AsPHAltoId
Asphaltites are a variety of naturally occurring, dark brown to black, solid, nonvolatile bituminous
substances that are differentiated from bitumen primarily by their high content of material insoluble
in the common organic solvents and high yields of thermal coke (Yurum and Ekinci, 1995). The
resultant high temperature of fusion (approximate range 115°C–330°C, 240°C–625°F) is characteristic. The names applied to the two rather distinct types included in this group are now accepted and
used for the most part without ambiguity.
Gilsonite was originally known as uintaite from its discovery in the Uinta Basin of western
Colorado and eastern Utah. It is characterized by a bright luster and a carbon residue in the range
10%–20% by weight. The mineral occurs in nearly vertical veins varying from about an inch to
many feet in width and is relatively free of occluded inorganic matter. Samples taken from different veins and across the larger veins may vary somewhat in softening point, solubility characteristics, sulfur content, and so on, but the variation is not great. It is evident in all instances that it is
essentially the same material, and it is therefore appropriate to apply a single name to this mineral.
However, caution should be exercised in using the same term without qualification for similar materials until it can be shown that they are equivalent to gilsonite.