Oil royalty distributions in Illinois

I have shares in oil royalties but can find no information about distribution from 1989 to 1994 or there abouts. It appears someone didn’t probate their mothers will and continued to receive all royalties when they should have been split. Also, how to research if a supposedly dry well has been dug deeper. I’m new to this

Would suggest that you post in the county in Illinois where you have minerals if you do’t get an answer here.