Oil production methods vary from formation to formation, and determining how to extract, treat, refine and transport crude oil is largely a result of its API gravity measurement. API gravity is a direct indicator of an oil’s flow properties that affects every stage of production.
Light crude (oils with high API gravity) is typically easier to produce, transport and refine. However, as light crude deposits become depleted, producers are increasingly working with heavy, viscous oils, which have a unique set of challenges.
In this blog post, we’ll discuss the definition of API gravity, properties of heavy oil, and some solutions for heavy oil production and transportation.
API Gravity Scale
API gravity is a measurement of a crude oil’s density and is based on a scale established by the American Petroleum Institute (API). API gravity is the inverse of an oil’s density relative to water; essentially, how light or heavy an oil is compared to water. Oils with a high API gravity are lighter than water and less viscous, while oils with a low API gravity are heavier than water and are viscous.
The API gravity scale classifies crude as:
- Light crude: above 31º API
- Medium crude: 22-31º API
- Heavy crude: below 22º API
- Extra heavy crude: below 10º API
Not all industry groups use the same grading, and some classifications may vary slightly.
Oil produced in the Permian, Eagle Ford and Bakken formation is typically light, while oil from the Gulf of Mexico, California and Alaska is typically heavy.
As global light crude deposits decline, producers are shifting their focus to heavy crude deposits. The two largest oil deposits in the world are heavy crude and extra heavy crude found in the bitumen oil sands of Canada and Venezuela. The U.S. also has bitumen oil sands in California, Alaska, and Utah.
Extracting oil from bitumen sands, also known as tar sands, requires different techniques depending on the type of heavy oil and the properties of the rock. Most methods involve separation using water, oil, or solvents to soften and separate the oil from the sand. Once separated, some properties of heavy oil remain. Specific treatments, handling, and processes are required in order to transport and refine these heavy oils.
Heavy Oil Properties
Heavy oil is dense, thick, and highly viscous, making it more challenging to produce using traditional production methods. Heavy oils have more asphaltenes, averaging 12.7 weight percent compared to 2.5 weight percent in conventional oil. While paraffin is present in all crude oils, higher levels of asphaltene create problems with paraffin deposits. Asphaltenes mix with paraffin to create solids that bind to equipment and pipelines, causing blockages and restricting flow. With the lower API rating and higher viscosity of heavy oils, considerations must be made for how these properties affect production.
Solutions for Heavy Oil Production
Producing, transporting, and refining heavy oil means taking extra steps to reduce viscosity and keep the fluids flowing. Many chemical applications show positive results in reducing viscosity and increasing the flow of crude, such as:
- Low-dosage hydrate inhibitors
- Defoamers
- Paraffin inhibitors
- Hydrogen sulfide scavengers
- Asphaltene inhibitors
Operators have learned it is best to apply chemical additives early in the production process for long-lasting results. These treatments will see the crude through transport and keep it at optimum API gravity levels and viscosity for refining. Because the chemical properties of oil vary from formation to formation, producers must specifically tailor chemical treatments for the needs of each crude oil.
LamFloⓇ Viscosity Reduction
LamFloⓇ is a preventative treatment that breaks apart and suspends paraffin wax and asphaltenes, preventing buildups. It is aggressive on bitumen and other heavy oils, improving viscosity and lowering the pour point of lower API gravity oils. LamFloⓇ has low toxicity and an excellent environmental profile. It is biodegradable, and BTEX free making LamFloⓇ the right choice to preserve the environment and keep your pipelines flowing smoothly.
Contact Ideal Energy Solutions, LLC today for more formation about LamFloⓇ!
