Petroleum Production Operations Multiple Choice Questions on “Preventing or Removing Damage”.
1. Which of the following is more prone to damage during acidization?
a) Sandstone
b) Limestone
c) Dolomite
d) Shale
Answer: d
Clarification: Sandstones are more prone to damage during acidization. Emulsion – blocking and water – blocking is usually not a problem in Limestone and Dolomite reservoirs except during acidizing.
2. How much percentage (by volume) of surfactant is generally used in emulsion breaking tests?
a) 2 or 3 %
b) 4 or 5 %
c) 10%
d) 7%
Answer: a
Clarification: 2 or 3 % (by volume) of surfactant is generally used in emulsion breaking tests. The surfactant is added to the emulsion and then stirred with high-speed blender for 30 seconds.
3. How much percentage (by volume) of surfactant is generally used in the surfactant compatibility test?
a) 2 or 3 %
b) 4 or 5 %
c) 10%
d) 0.1 to 0.2 %
Answer: d
Clarification: 0.1 to 0.2 % (by volume) of surfactants are added to oil and water in surfactant compatibility test. The surfactant is added to the oil and water then stirred with high-speed.
4. A good surfactant should oil wet the surface of the rock.
a) True
b) False
Answer: b
Clarification: The statement is false. The corrected statement is that a good surfactant should water wet the surface of the rock. If the rock surface is not water wet then it’s going to reduce the relative permeability.
5. As a requirement for well treatment, the surfactant should prevent the formation of emulsions.
a) True
b) False
Answer: a
Clarification: The statement is true. As a requirement for well treatment, the surfactant should prevent the formation of emulsions and break emulsions previously formed. The other requirements are it should not swell or shrink.