Characterization of Crude Oil

Which of the following is the standard in quality measurement of petroleum and refined products properties?

• ANSI

• API

• SPC

• ASTM

Answer explanation

ASTM's (American Society for Testing and Materials) petroleum standards are instrumental in the evaluation and assessment of the physical, mechanical, rheological, thermal, and chemical properties of crude oils, lubricating grease, automobile and aviation gasoline, hydrocarbons, and other naturally occurring energy resources used for various industrial applications. These fuels are tested for their composition, purity, density, miscibility and compatibility with other fluids and materials, toxicity, and thermal stability among others. These petroleum standards allow petroleum refineries, automotive and aviation companies, and other geological and chemical processing plants to appropriately examine and process these fuel oils ensure their quality towards safe and efficient use.

More info: https://www.astm.org/products-services/standards-and-publications/standards/petroleum-standards.html

How can you characterize the crude oil based on high and low pour point?

• high pour point - high paraffin content & low pour point - high aromatic content

• low pour point - high paraffin content & high pour point - high aromatic content

• low pour point - low paraffin content & low aromatic content

• high pour point - high paraffin content & high aromatic content

Answer explanation

Pour Point - The temperature at which the liquid becomes semi-solid and loses its flow characteristics.

 

High pour point is associated with high paraffin content, otherwise it is aromatics.

Sulphur, nitrogen, metals and salts are possible impurities found in the crude oil. What are the consequences with the present of these impurities in crude oil?

• corrosion of metals

• poisoining the catalyst

• reduce the carbon and hydrogen in crude oil

• fouling of crude oil

Answer explanation

salt - can cause fouling and corrosion to equipment

nitrogen, sulphur and metals can poison the catalyst and cause corrosion to equipment

1.     A well was discovered with crude oil density of 7.2 ppg (lb/gal). Calculate the API gravity of the crude oil.

[Note: density of water = 8.33 ppg or 1.0 gcm-3; ppg = pound per gallon]

• 25.0^o

• 45.5^o

• 32.2^o

• 10.0^o

Answer explanation

How can we categorise if the crude oil is sweet?

• less than 0.5 % sulfur content

• more than 0.5 % sulfur content

• less than 5 % sulfur content

• more than 5 % sulfur content

Answer explanation

Sweet is when the crude oil contains less than 0.5% of sulfur and sour is when the sulfur content is above 0.5%.

Sweet oil is in demand because sour crude oil can cause damages to the equipment i.e. corrosion, hydrogen sulfide gas may be formed as well which is very toxic to people and environment. It will be costly to deal with high content sulfur.

Which of the following is not crude oil benchmark?

• West Texas Intermediate (WTI)

• Brent Crude

• PB Light

• Bonny Light

Which of the two properties are important on crude oil transportation through the pipeline?

• Kinematic Viscosity

• Boiling Point

• Pour Point

• Melting Point

Answer explanation

Pour point - is the lowest temperature before the substance becoming semi-solid

Kinematic Viscosity - refer to the viscous of the fluid. High Viscosity refers to thicker hydrocarbon and slower the flow.