Types of Crude Oil
Oil investors and consumers are generally interested in the quality of oil. This is due to the fact that crude oil forms differently due to the geographical diversity of different locations. Crude oil is then classified into several categories depending on its density and sulfur content and then it is refined for end-user consumption. This categorization is performed by the oil industry and regulators and is one of the factors which determines oil price apart from geopolitics, natural events and organizational influences. This blog discusses the various grades of crude oil and their individual characteristics which play important roles in the oil and gas industry.
EPA Classifications for Crude Oil
The Environment Protection Authority (EPA) categorizes crude oil into four main types of crude oil: Class A, Class B, Class C, and Class D. These are important for learning more about general toxicity and physical state changes:
Class A: Most refined products and many high-quality, light crude oils are included in Class A. Class A oils are highly fluid, often clear, spread rapidly on solid or water surfaces and are usually flammable. Despite how valuable they are, Class A oils can be extremely toxic to humans, animals, and other organisms.
Class B: These are waxy and oily in feel and are less toxic than Class A oils. They stick more firmly to surfaces than Class A oils. As temperatures rise, their tendency to penetrate porous substrates increases and they can be persistent. Evaporation of volatiles may lead to a Class C or D residue. Medium to heavy paraffin-based oils fall into this class.
Class C: These are usually brown or black, have a similar density to water, and tend to sink. This type of oil doesn’t penetrate porous surfaces as quickly as other types of crude oil. In the event of evaporation or weathering of volatiles in a Class C oil, it may produce solid or tarry Class D oil. Even though Class C crude oil is less toxic, it can still harm wildlife.
Class D: These are residual oils, heavy crude oils, select high paraffin-based oils, and certain weathered oils. Typically, Class D oils are dark black or brown, and if they melt, they can coat surfaces, making cleaning up a spill very difficult. Class D crude oil is relatively nontoxic and do not penetrate porous substances.
Industry Classifications of Crude Oil
Oil can be grouped by sulphur content as either sweet or sour, or by density as either heavy or light. Using these two groups—and by creating a group in between—oil is classified into six classes by the industry and investors:
Heavy/Sweet, Heavy/Sour, Medium/Sweet, Medium Sour, Light/Sweet, Light/Sour
Heavy oils are used to make industrial products like asphalt and plastics. Medium oils have sulphur content that falls somewhere between heavy and light. Light oils are generally used in diesel, gasoline, and aviation fuel because they take less processing. Sour crude has more sulphur and carbon than light crude and requires more refining using steel fabrication; thus, it incurs more costs.
Closing Comments
The broad categorization of oils leads to its varied uses in petroleum and petroleum-derived industries. However, for oil spills, these classifications are dynamic as weather conditions and water temperature greatly influence the behaviour of oil and refined petroleum products in the environment. Thus, there is a lot of granularities with regard to types of crude oil pertaining to chemical composition, characteristics, uses etc. and this showcases how crude oil plays different roles in our day-to-day lives!