250+ TOP MCQs on Environments – Petroleum Industry and Answers

Corrosion Engineering Multiple Choice Questions on “ Environments – Petroleum Industry”.

1. Which of the following is/are the general areas of the petroleum industry that faces corrosion problems?
a) Production unit
b) Transportation and storage
c) Refinery operations
d) Production unit, transportation, storage, and refinery operations
Answer: d
Clarification: The Petroleum industry is one of the most affected industries with corrosion. The general areas of the petroleum industry that faces corrosion problems are production unit, transportation, storage, and refinery operations.

2. Which of the following impurities is often present in oil and gas wells?
a) Saline water
b) Sulfides
c) Saline water, sulfides and organic impurities such as ammonia
d) Organic impurities such as ammonia
Answer: c
Clarification: Oil and gas fields consumes a tremendous amount of iron and steel pipe, tubing, casings, pumps, and valves. Saline water, sulfides, and organic impurities such as ammonia are the impurities that are usually present in oil and gas fields.

3. How the corrosion characteristics of a well can be determined?
a) Inspection of surface equipment
b) Analysis of carbon dioxide and organic acid
c) Tubing-caliper surveys
d) Inspection of surface equipment, analysis of carbon dioxide, organic acid and tubing-caliper surveys
Answer: d
Clarification: Corrosion characteristics of a well is determined by
i. Inspection of surface equipment
ii. Analysis of carbon dioxide and organic acid
iii. Coupon exposure tests
iv. Tubing-caliper surveys.

4. Which of the following is/are the neutralizers added to well to minimize corrosion?
a) Ammonia and Sodium carbonate
b) Ammonia, sodium carbonate, sodium hydroxide, and sodium silicate
c) Ammonia and sodium silicate
d) Sodium carbonate and sodium silicate
Answer: b
Clarification: Neutralizers that are added to petroleum to minimize corrosion are:
i. Ammonia
ii. Sodium carbonate
iii. Sodium hydroxide
iv. Sodium silicate and some organic inhibitors.

5. Which of the following metals is/are used for petroleum well valves and wellhead parts?
a) Straight chromium stainless steels and stellite
b) Monel and copper-based alloys
c) Monel, straight chromium steels, stellite, and copper-based alloys
d) Monel and stellite
Answer: c
Clarification: Metals that are usually used for petroleum well valves and wellhead parts are straight chromium stainless steels, stellite, monel, and copper-based alloys.

6. Which of the following prevention methods that are usually employed on a beam of offshore drilling?
a) Paints and other organic coatings
b) Cathodic protection with sacrificial anodes or impressed currents
c) Adding inhibitors
d) Adding inhibitors, paints and other organic coatings and cathodic protection
Answer: d
Clarification: Preventions methods that are usually employed on a beam of offshore drilling are:
i. Paints and other organic coatings
ii. Cathodic protection with sacrificial anodes or impressed currents
iii. Adding inhibitors.

7. Which of the following inhibitor has been effective for internal corrosion domestic fuel oil tanks?
a) Alkaline sodium chromate
b) Sodium silicate
c) Ammonia
d) Sodium carbonate
Answer: a
Clarification: Alkaline sodium chromate or sodium nitrate is an effective inhibitor for the corrosion of domestic fuel oil tanks. The chemical formula of sodium chromate is Na₂CrO₄.

8. Which of the following impurities that causes corrosion difficulties in refinery operations?
a) Hydrogen sulfide and carbon dioxide
b) Hydrogen sulfide, carbon dioxide, sulfuric acid, and sodium chloride
c) Sodium carbonate and sodium silicate
d) Hydrogen sulfide and sulfuric acid
Answer: b
Clarification: Refinery of crude is done based on the difference in boiling points of the components present and the process is known as fractional distillation. Hydrogen sulfide, carbon dioxide, sulfuric acid, and sodium chloride are the impurities that cause difficulties in refinery operations.

9. Water acts as an electrolyte and causes corrosion as it tends to hydrolyze chlorides and other materials to form an acidic environment.
a) True
b) False
Answer: a
Clarification: Water acts as an electrolyte and causes corrosion in refining operations. This is because water tends to hydrolyze chlorides and other materials to form acidic environments.

10. Which of the following is/are the desalting methods in the petroleum industry?
a) Washing and settling
b) Addition of chemicals such as sulfonates
c) Centrifuging and filtering, washing and settling, the addition of chemicals such as sulfonates
d) Centrifuging and filtering
Answer: c
Clarification: Desalting methods in the petroleum industry are:
i. Washing and settling
ii. Addition of chemicals such as sulfonates
iii. Centrifuging and filtering.

11. Ammonia is used to control the pH of the water and to reduce chloride acidity in the process stream.
a) True
b) False
Answer: a
Clarification: Ammonia is used to control the pH of the water and to reduce chloride acidity in the process streams. It usually maintains a pH of 7 but it damages copper-bearing alloys if the pH becomes 8 or more.

12. Which of the chemical is/are added for the removal of hydrogen sulfide and neutralization?
a) Sodium hydroxide
b) Lime
c) Sodium hydroxide and lime
d) Naphthenic acid
Answer: c
Clarification: Sodium hydroxide and lime are/are added for the removal of hydrogen sulfide and neutralization during the refining of petroleum. NaOH and CaO are the chemical formulae of sodium hydroxide and lime respectively.

13. Which of the following impurity that causes rapid intergranular stress corrosion cracking of sensitized austenitic stainless steels in refinery operations?
a) Sodium chloride
b) Naphthenic acid
c) Hydrogen sulfide
d) Carbon dioxide
Answer: b
Clarification: Naphthenic acid causes rapid intergranular stress corrosion cracking of sensitized austenitic stainless steels in refinery operation. Whereas naphthenic acid is a combination of cyclopentyl and cyclohexyl carboxylic acids.

14. Which of the following metals is/are usually used for heat exchanger tubes carrying water?
a) Carbon steels
b) Brass and cupronickels
c) Arsenical admiralty metal
d) Brass, cupronickels and arsenical admiralty metal
Answer: d
Clarification: Brass, cupronickels, and arsenical admiralty metal are usually used for heat exchangers tubes carrying water. Whereas carbon steels are unsuitable as it rapidly corrodes by the cooling water.

15. Which of the following element is the most beneficial alloying element in steel for resistance to sulfur compounds?
a) Chromium
b) Nickel
c) Molybdenum
d) Carbon
Answer: a
Clarification: Chromium is the most beneficial alloying element in steel for resistance to sulfur compounds. As per the study, 2.25% chromium and 1% molybdenum is required for less than 0.2% H₂S in the gas.