Step 1: Recall what each curve represents.
- \(C1\): Resulting burst pressure (solid line with dots).
- \(C2\): Pressure inside casing/open hole.
- \(C3\): Burst strength of casing (dotted line).
- \(C4\): Fracture strength (dashed line).
For wellbore integrity:
- The pressure profile must remain within casing strength (C3) and fracture limit (C4).
- Any crossing/violation indicates reduced integrity.
Step 2: Profile 1 analysis.
In Profile 1, the operating pressure line approaches and exceeds fracture strength line (C4).
This means the formation cannot hold pressure → failure due to weak formation.
\[
\Rightarrow \text{Profile 1 → Reduced wellbore integrity (weak formation)}.
\]
Step 3: Profile 2 analysis.
In Profile 2, the operating pressure line approaches the casing burst strength (C3).
This means casing fails before the formation → failure due to weak casing.
\[
\Rightarrow \text{Profile 2 → Reduced wellbore integrity (weak casing)}.
\]
Step 4: Profile 3 analysis.
In Profile 3, the operating pressure lies safely between casing strength (C3) and fracture strength (C4).
This indicates that both casing and formation are safe → full wellbore integrity.
\[
\Rightarrow \text{Profile 3 → Full wellbore integrity}.
\]
Step 5: Match results.
- P (Profile 1) → I (weak formation).
- Q (Profile 2) → II (weak casing).
- R (Profile 3) → III (full integrity).
Final Answer:
\[
\boxed{\text{(A) P – I; Q – II; R – III}}
\]