Fifth Circuit Holds Co-Tenant Drilling Does Not Satisfy Unless Clause for Separate Undivided Interest Lease

The Fifth Circuit affirmed termination of an oil and gas lease covering an undivided interest where the lessees failed to pay delay rentals or commence drilling operations, holding that drilling by another company holding a lease on different undivided interests in the same tract could not satisfy the unless clause. The court rejected appellants' argument that production language in the habendum clause permitted them to hold the lease without providing consideration through their own drilling operations.