When looking at different types of crude oil for purchase, oil refineries will look at many measures, one of which is known as the API gravity metric. API is a measurement developed by the American Petroleum Institute. It is used to calculate the density of oil, and, for refinement purposes, the lighter the oil the better.
A recent study produced by the Energy Information Administration stated that the lower 48 states have had nearly 51% of their crude oil measure higher than 40 degrees on the API scale for the first nine months of 2015. This means that 51% of oil is considered light and highly desirable. Texas surpasses the norm, with 20% of its produced oil having a 50 degree API gravity or higher. Nationally, only 11% of oil produced is above the 50 API gravity mark.
Most types of oil fall into one of three categories: heavy, mid or light. Of course, densities vary greatly, and some types of oil do not fall directly into one category. Texas produces many valuable types of light crude oil used in national production. Lighter crude oil is in higher demand than its lower counterparts, and is therefore, more expensive. However, purchased oil has been usually been mixed with other crude oil from multiple sources, leading to different densities and different amounts of sulfur within. This can cause some issues for refining companies, which must separate the different types of crude oil in order to individually process them.
It is extremely difficult to develop standardized processes when trying to account for multiple types of oil. New technologies that assist in the process of separating different types of oil are constantly being researched. In the coming years we should see advancements in these processes which will lead to higher efficiency and profitability.
Article written by HEI contributor Timothy McNally.