Classification of petroleum

A widely used classification of petroleum distinguishes between crude oils either on a paraffin base or on an asphalt base and arose because paraffin wax separates from some crude oils on cooling, whereas other oils show no separation of paraffin wax on cooling. The terms paraffin base and asphalt base were introduced and have remained in common use (van Nes and van Westen, 1951). 

Chemical classifications of petroleums relate to the molecular structures of the molecules in the oil. Of course the smaller molecules, six carbon atoms and less, are predominately paraffins. So chemical classification is usually based on analysis of the petroleum after most of the light molecules are removed. 

Clapp, F.G. 1910. A proposed classification of petroleum and natural gas fields. Econ. Geol., 5 503-521. 

Wilhelm, O. 1945. Classification of petroleum reservoirs. Am. Assoc. Pet. Geol. Bull., 29 1537-1580. 

In all of these attempts at a definition or classification of petroleum, it must be remembered that petroleum exhibits wide variations in composition and properties, and these variations not only occur in petroleum from different fields but may also be manifested in petroleum taken from different production depths in the same well. The mixture of hydrocarbons is highly complex. Paraffinic, naphthenic, and aromatic structures can occur in the same molecule, and the complexity increases with boiling range of the petroleum fraction. In addition, petroleum varies in physical appearance from a light-colored liquid to the more viscous heavy oil. The near-solid or solid bitumen that occurs in tar sand deposits is different from petroleum and heavy oil, as evidenced by the respective methods of recovery (Speight, 1999,2000). 

GENERAL PROPERTIES AND CLASSIFICATION OF PETROLEUM COMPARISON OF PETROLEUM FROM DIFFERENT COUNTRIES... 

It is necessary to make a chemical classification of petroleum since chemical properties are very crucial in selecting the right method for processing the oil. There are many classifications with regard to fractions and chemical compositions of petroleum. In this chapter we will present the basis for these classification methods. 

The chemical classification of petroleum that distinguishes between oils of a paraffin base from those of an asphaltene base was introduced into petroleum chemistry to distinguish the oils that separate paraffin on cooling from those that separate asphaltenes. The presence of paraffins is usually reflected in the paraffinic nature of the constituent fractions whereas a high asphaltic content corresponds with the naphthenic properties of the fractions. This could lead to the misconception that paraffin-base petroleum consists mainly of paraffins and that asphalt-base petroleum consists mainly of cyclic (or naphthenic) hydrocarbons. In order to avoid confusion, a mixed base has been introduced for those oils that leave a mixture of asphaltic petroleum and paraffins as residue from nondestruc-... 

MS ISO 8216/0 establishes the general classification of petroleum fuels (fuels of class F). There are five categories of products which are included in class F. These categories depend on the type of fuel. 

ISO 8216/0-86 - Classification. Part 0. This is a general classification of petroleum fuels (Class F). The Russian equivalent for this standard is GOST 28577.0-90. 

Table 1.4 shows the international classification of petroleum fuels. 

Classification of petroleum lubricating oils according to the type of crude they come from or the refining procedures used to obtain them is neither illogical nor grossly empirical. The physical and chemical properties of an oil depend on its composition, which in the last analysis is determined by the composition of the crude. Thus the nature... 

Fig. 1. Regional framework in this study. BCU map of the Tampen Spur area, with geochemical classification of petroleum populations (Horstad et al. 1995).

Attempted Classification of Petroleum, Heavy Oil, and Tar Sand Bitumen by Density-Gravity Type of Crude Oil... 

Various classifications of petroleum are reported in the literature, which take into consideration crude oil properties, distillates properties, chemical structure, origin, etc. Given the great amount of effort that experts around the world have put into these definitions, it is not necessary to generate new criteria. 

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