FROST NATIONAL BANK IND. EX. -B- #21 C

Permit records can indicate requested drilling, recompletion, deepening, or related work, but do not guarantee drilling or production.

Completion filings can show that a well moved from permitted or drilled status into a completed well record.

Production signals help identify wells with linked monthly production or derived producing status.

P-4 activity can indicate operator, lease, gatherer, purchaser, or responsibility changes tied to the record.

Plugging notices and plugging records help distinguish planned plugging from wells already reported as plugged.

Directional surveys, plats, and L-1 records can be important for understanding horizontal wells beyond the surface point.