A first arrival amplitude of the Cement Bond Log (CBL) of a cased hole section is given in the figure. The identified depth intervals P, Q, and R represent
A first arrival amplitude of the Cement Bond Log (CBL) of a cased hole section is given in the figure. The identified depth intervals P, Q, and R represent
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- P: not cemented; Q: partially cemented; R: well-cemented
- P: not cemented; Q: well-cemented; R: partially cemented
- P: partially cemented; Q: not cemented; R: well-cemented
- P: well-cemented; Q: not cemented; R: partially cemented
The Correct Option is D
Solution and Explanation
- In Cement Bond Log, the first arrival amplitude indicates the quality of cement bonding between casing and formation.
- High amplitude $\Rightarrow$ poor bonding (not cemented).
- Low amplitude $\Rightarrow$ strong bonding (well cemented).
- Intermediate amplitude $\Rightarrow$ partial cementation.
Step 2: Interpretation of zones.
- Zone P shows very low amplitude $\Rightarrow$ good bond $\Rightarrow$ well-cemented.
- Zone Q shows very high amplitude $\Rightarrow$ poor bond $\Rightarrow$ not cemented.
- Zone R shows moderate amplitude $\Rightarrow$ partial bond $\Rightarrow$ partially cemented.
Thus, the answer is (D): P = well-cemented, Q = not cemented, R = partially cemented.
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