250+ TOP MCQs on Geologic Considerations – Traps for Oil and Gas Accumulation and Answers

Petroleum Production Operations Questions and Answers for Freshers on “Geologic Considerations – Traps for Oil and Gas Accumulation”.

1. The Cap rock should have very high permeability?
a) True
b) False
View Answer

Answer: b
Clarification: The Cap rock should have very less permeability in order to restrict the flow of hydrocarbons or to accumulate hydrocarbons in the reservoir rock. The reservoir rocks on the other hand are that type of rocks that hold the hydrocarbons within it and have good porosity and permeability.

2. How many types of traps are there?
a) 5
b) 2
c) 3
d) 4
Answer: c
Clarification: There are 3 types of traps. These are Structural traps, Stratigraphic traps and Strati-structural traps. Traps that are formed by structural deformation are known as Structural traps. Traps that are associated with the depositional or diagenetic features are known as Stratigraphic traps. Traps formed by combination of the both above mentioned process are known as Combination or Strati-structural traps.

3. Which type of fold is this?

a) Anticline
b) Syncline
c) Antiformal Syncline
d) Synformal Anticline
Answer: a
Clarification: This is an Anticline because it is clear from the picture that the older rock lies beneath the younger layer i.e. the layer which deposited later on after the older rock was deposited.

4. Name the type of Fold shown in the diagram below.

a) Anticline
b) Syncline
c) Antiformal Syncline
d) Synformal Anticline
Answer: d
Clarification: This is a Synformal Anticline because it is clear from the picture that the older rocks are lying above the younger rocks in a concave upward manner.

5. Gas-Oil contact lies above the Water-Oil contact.
a) True
b) False
Answer: a
Clarification: Gas-Oil contact lies above the Water-Oil contact because the density of water> Oil > Gas. So water lies at the bottom followed by Oil then Gas at the top. So GOC will be above the WOC.

6. What will happen if we drill a salt-dome?
a) We’ll get hydrocarbons
b) We’ll get Water
c) It may collapse
d) Salt will be produced.
View Answer

Answer: c
Clarification: If we drill a salt-dome then it’ll collapse. The salt domes do not have that much strength to hold it intact while drilling. The hydrocarbons are accumulated not inside the salt domes but near the salt domes if proper seal rock and a good reservoir rock is there.