API Gravity

1. Definition

API Gravity is a measure of how heavy or light a petroleum liquid is compared to water, established by the American Petroleum Institute. * It determines the density of the crude oil. * Inverse Relationship: Although it's called "gravity," the scale is inverted. Higher API numbers mean lower density (lighter oil).

2. The Scale

• Water = 10 degrees.
• API > 10: The oil is lighter than water and floats on it.
• API < 10: The oil is heavier than water and sinks.

3. Classification & Value

Generally, higher API (Lighter) commands a higher market price.

1. Light Crude (API > 31.1):
   • Low viscosity, flows freely.
   • Yields a high percentage of gasoline and diesel fuel when refined.
   • Examples: WTI (~39.6), Brent (~38.3).
2. Medium Crude (API 22.3 ~ 31.1):
   • Example: Dubai (~31).
3. Heavy Crude (API < 22.3):
   • Highly viscous (like molasses). Requires more complex and expensive refining processes (Cracking) to produce usable fuels.

4. Economic Implication

Refineries are configured for specific API ranges. * "Light" oil is easier to process into high-value fuels. * "Heavy" oil requires sophisticated "Complex Refineries" (like those in South Korea or the US Gulf Coast) to break down heavy hydrocarbons into valuable products.