A more thorough explanation:

An entirety clause is a provision in a mineral lease or deed that states that royalties must be divided if the property is divided after the lease is granted. This means that if the owner of the property decides to sell or lease a portion of the land, the royalties from the oil and gas extracted from that portion will be divided between the original owner and the new owner.

For example, let's say that John owns a piece of land and leases it to an oil company for drilling. The lease agreement includes an entirety clause. A few years later, John decides to sell a portion of the land to his neighbor, Jane. If the oil company continues to extract oil and gas from the entire property, the royalties will be divided between John and Jane. John will receive royalties for the portion of the land he still owns, and Jane will receive royalties for the portion she purchased.

The purpose of an entirety clause is to ensure that all parties involved are aware of their rights and responsibilities if the property is divided. It also helps to prevent disputes between the original owner and any new owners.