What is the name for the lowest point of closure on a structural trap which defines the maximum possible size of the trap?

What is the name for the lowest point of closure on a structural trap which defines the maximum possible size of the trap?

• A. Trap Apex
• B. Spill Point
• C. Apex Point
• D. Limit Point

Answer: (B)

The main idea here is the spill point: the lowest point of closure on a structural trap that determines how large the trap can become. In a closed trap, hydrocarbons migrate in and pool against the sealing rock until the column reaches this lowest shut point. At that level, the trap would spill if it were breached, so the spill point caps the vertical extent and sets the maximum amount of hydrocarbons the trap can hold. Terms like trap apex or apex point describe the highest point of closure, not the lowest, while limit point isn’t the standard term for this feature. That’s why spill point is the best match.

The main idea here is the spill point: the lowest point of closure on a structural trap that determines how large the trap can become. In a closed trap, hydrocarbons migrate in and pool against the sealing rock until the column reaches this lowest shut point. At that level, the trap would spill if it were breached, so the spill point caps the vertical extent and sets the maximum amount of hydrocarbons the trap can hold. Terms like trap apex or apex point describe the highest point of closure, not the lowest, while limit point isn’t the standard term for this feature. That’s why spill point is the best match.