Petroleum Production Operations Multiple Choice Questions on “Well Stimulation with Surfactants”.
1. Surfactants are the surface-active chemicals that contain at least two functional groups.
a) True
b) False
Answer: a
Clarification: The statement is true. Surfactants are the surface-active chemicals that contain at least two functional groups. One part is soluble in oil and another part is soluble in water. The molecule thus is partially soluble in both water and oil.
2. How can the Surfactants increase the interaction between water and oil?
a) By decreasing the pressure
b) By increasing the oil-water interfacial tension
c) By decreasing the oil-water volume
d) By decreasing the oil-water interfacial tension
Answer: c
Clarification: Surfactants can increase the interaction between the water and oil by decreasing the oil-water interfacial tension. A surfactant can also alter the wettability of the surface of the rock.
3. Various wettability measurements are described in API RP – 42.
a) True
b) False
Answer: a
Clarification: The statement is true. Various wettability measurements are described in API RP – 42. Wettability plays a vital role. Oil wet rock is unfavorable as compared to water wet rock surface.
4. A surfactant used to remove or prevent formation damage should ____ the surface or interfacial tension.
a) Increase
b) Remain constant
c) Not alter
d) Decrease
Answer: d
Clarification: A surfactant used to remove or prevent formation damage should decrease the surface or interfacial tension. The surfactant should not swell nor shrink. It should not disturb the formation of clays.
5. To overcome the difficulty of losing the surface activity of the surfactants above 50,000 ppm salt which of the following is required?
a) After the flush of low saline water
b) After the flush of high saline water
c) Pre-flush of low saline water
d) Pre-flush of high saline water
Answer: c
Clarification: To overcome the difficulty of losing of the surface activity of the surfactants above 50,000 ppm salt, Pre-flush of low saline water e.g. 1% KCl is used which is seemed to be very useful in well treatments.