you are probably looking at a P-16 form if you are in Texas. It is used for "allocation" wells, where the operator spans several leases and is allocating acreage to each well. I have a number of them, and have yet to figure out how they related to your specific well. My advice, unless someone here has better experience, is to contact the operator's land department and ask them to help you understand your acreage and how it relates to the overall royalty interest. They can, but generally don't like to, send you a copy of your section of a drilling title opinion.