Question

Which of the following statement(s) is/are CORRECT about polymer flooding?

• A. Viscous fingering in the reservoir decreases.
• B. Viscosity of the displaced fluid increases.
• C. Mobility of the displaced fluid increases.
• D. Mobility ratio decreases.

Hint:

In enhanced oil recovery techniques such as polymer flooding, increasing the viscosity of the injected fluid reduces viscous fingering and improves the sweep efficiency, which helps recover more oil from the reservoir.

Answer 1

The Correct Option is A, D

Polymer flooding is an enhanced oil recovery (EOR) technique where a polymer solution is injected into the reservoir to improve the displacement of oil. The polymer increases the viscosity of the injected fluid, which helps to push the oil more effectively.
- Option (A) is correct because by increasing the viscosity of the injected fluid, polymer flooding reduces the tendency for viscous fingering, which is when the injected fluid moves through the reservoir in a finger-like pattern, bypassing the oil. This improves the sweep efficiency of the flooding process.
- Option (B) is incorrect because the viscosity of the displaced fluid typically increases during polymer flooding, but the focus is on reducing the viscosity contrast between the oil and the injected fluid.
- Option (C) is incorrect because the mobility of the displaced fluid actually decreases with polymer flooding, as the viscosity of the injected fluid is higher, reducing its ability to move quickly through the reservoir.
- Option (D) is correct because polymer flooding helps to decrease the mobility ratio, which is the ratio of the mobility of the displacing fluid (the polymer solution) to the mobility of the displaced fluid (oil). A lower mobility ratio reduces the likelihood of early breakthrough and improves recovery efficiency. Thus, the correct answers are options (A) and (D).