# Crude Oil

> Crude oil is traded by grade. Yorkwell Petroleum trades and brokers crude oil for buyers whose refineries are set up for particular grades.

URL: https://yorkwellpetroleum.com/energy-commodity-trading/crude-oil/

## How a crude grade is described

Each crude grade has its own density and sulfur content. Density is expressed as API gravity: the higher the number, the lighter the oil.

Sulfur decides whether a crude is sweet or sour. Crude with less than 0.5% sulfur is commonly called sweet, and crude with more is called sour. West Texas Intermediate is a well-known sweet benchmark.

| Class | API gravity |
| --- | --- |
| Light | Above 31.1° |
| Medium | 22.3° to 31.1° |
| Heavy | Below 22.3° |
| Extra heavy | Below 10.0° |

These classes are common, but not every party uses the same grading. The contract names the grade and its limits.

## Why the assay matters

An assay is a laboratory analysis of a crude grade. It shows the oil's properties and the yields of products it gives when refined. A refinery uses the assay to decide whether a grade suits its units, so buyers ask for it early in a trade.

## How a crude trade is handled

- The buyer names the grade or quality range, the quantity and the delivery window.
- The seller provides the assay and the origin documents.
- An independent inspector measures quality and quantity at loading.
- Delivery terms and the pricing basis are fixed in the contract.

## Questions we are asked

### Which crude grades can you offer?

Grades and origins change with supply. Tell us the grade or quality range your refinery needs.

### How is crude oil priced?

Price is usually set against a published benchmark, such as WTI or Brent, plus or minus a differential agreed in the contract.

### How do I make an inquiry?

Send the grade, quantity, destination and delivery window through our [contact page](https://yorkwellpetroleum.com/contact-us/).

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Yorkwell Petroleum · 440 Louisiana St, Ste 900, Houston, TX 77002 · info@yorkwellpetroleum.com · +1 (713) 239-3396