Important to understand that Not all Crude Oils are the same. different crudes not just have different ingredients but also different qualities. Some crude oils are preferred over others by the Refiners. Hence, we have different Price for each different quality of Crude oil.

The reason crude oils from various locations are of higher and lower quality is that of the Geologic Processes that produce the crude oil. All crude oil is found in sedimentary rock. Different crude oil types are the results of the different sedimentary rock types.

So, what is High Quality and What is Low Quality Oil?

The Sulfur content and the Weight are the two qualities by which crude oil is typically judged/priced. High-Sulfur + heavy oils are the lowest quality and the least expensive on the global market. Low-Sulfur + light oils bring the highest price because they are of the highest quality.

Let's talk briefly about each quality

1- High Vs Low Sulfur Oil

In the Petroleum industry these are called Sweet and Sour Oils. Oils with which is low in Sulfur will taste sweet and bitter when Sulfur is high. Historically, when a well began to produce, prospectors would taste the oil to determine its quality. Sweet crude tastes as the name implies and sour crude oil tastes rotten. In short, the more Sulfur crude oil contains, the less energy it produces per gallon, barrel, or litre.

2- Heavy Vs Light Oil

American Petroleum Institute (API) Gravity is the measure of the weight of crude oil. It is calculated using the following formula API = 141.5/SG - 131.5. So, if an oil’s API Gravity is greater than 10, it is lighter than water and will float on it. If an oil’s API Gravity is less than 10, it is heavier than water and will sink. There are 4 classifications of API gravity: Light Oils (31.1 - 45.4), Medium (22.3 - 30.2), Heavy (10.0 - 21.5), and Extra Heavy (0.1 - 6.5).