Petroleum Production Operations Multiple Choice Questions on “Geologic Considerations – The Habitat of Oil and Gas”.
1. Most oil and gas reservoirs are found in which of the following formations?
a) Sandstone and Shale
b) Sandstone and Evaporites
c) Carbonate and Shale
d) Carbonate and Sandstone
View Answer
Answer: d
Clarification: Most oil and gas reservoirs are found in Carbonate and Sandstone formations. They are called reservoir rocks and they have good porosity and permeability in most of the cases. On the other hand, Shale and Evaporites work as cap rocks having less permeability.
2. The habitat of oil and gas in the sub-surface is known as ______
a) Oil Habitat
b) Resources
c) Gas Habitat
d) Reservoir
Answer: d
Clarification: The habitat of oil and gas in the sub-surface is known as Reservoir. A petroleum reservoir is a rock that contains hydrocarbons in the pores and fractures.
3. Which porosity should be high to be a good producing reservoir and contribute to fluid flow through its porous media?
a) Effective porosity
b) Absolute porosity
c) Primary porosity
d) Secondary porosity
View Answer
Answer: a
Clarification: Effective porosity should be high to be a good producing reservoir. It is that type of porosity in which we consider only those pores which are interconnected and contribute to the fluid flow. Absolute porosity is that porosity which doesn’t depend on whether the pores are interconnected or not. Primary porosity is the porosity which arises when the sediment was deposited and the porosity which arises after the deposition of the rock is called Secondary porosity.
4. The general physical characteristics of rocks are known as________
a) Lithology
b) Hydrology
c) Strata
d) Rock Mechanics
Answer: a
Clarification: The general physical characteristics of rocks are known as Lithology. Physical characteristics include color, texture, grain size and composition.
5. Which of the following rock has isolated bound water containing within it?
a) Sandstone
b) Carbonate
c) Siltstone
d) Shale
Answer: d
Clarification: Shale has isolated bound water containing within it. Shale has very less permeability. Sandstones and Carbonates are generally reservoir rock. Shale is known as cap rock. Siltstone is a sedimentary rock that contains grains, which lies in the silt range.
6. To be a good reservoir rock the porosity and permeability should be low?
a) True
b) False
View Answer
Answer: b
Clarification: The porosity and permeability should be high to be a good reservoir rock. If the porosity is very low then the rock can’t accumulate a good amount of hydrocarbons within it. So the porosity should be high. And for the hydrocarbon to flow it should have good permeability.