• wellhead,
• wellheadz,
• welheads,
• wellhads,
• wellheds,
• qell heads,
• aell heads,
• sell heads,
• eell heads,
• 3ell heads,
• 2ell heads,
• wwll heads,
• wsll heads,
• wdll heads,
• wrll heads,
• w4ll heads,
• w3ll heads,
• wekl heads,
• wepl heads,
• weol heads

The adjective form of "well heads" is "well-headed".

The plural form of "well head" is "well heads".

The singular form of the word "well heads" is "well head".