Gas well drilled after death (back royalties)

Hi,

My great-uncle owned land (and mineral rights as they were never severed) in Texas since the 1960s.

He died in 2002 leaving a will.

In 2005, a gas company decided to drill a well on his land and it has been in steady production until today.

My uncle (who was caretaker of G-U) recently had G-U’s will probated outside of the 4-year Texas window as Muniment of Title.

How does my uncle go about getting any and all royalties from this well?

Nothing has been given to the state as escheatment.

Is he due royalties all the way back to 2005 or has that ship sailed and he can only recoup the previous 4 years (I read something about a 4-year window for underpayment someplace).

Thanks.

Who signed the lease in 2005? And did the entire probate proceeding go smoothly such that the Will was Probated as a muniment of title? I wouldn’t be surprised if the gas company has all the funds in suspense from the interest which could make it was to get released once all the proceedings are finalized. But it’s fishy that a lease was signed in 2005, because if the will was not probated but was still in the 4 year window for probating, I don’t know how the gas company could have figured out who to get to sign the lease. If you give me a few more details, I can help a little better.