Nonapportionment Rule [Oil & Gas] Law and Legal Definition
Nonapportionment rule is a principle of oil and gas law that the royalties accrued under a mineral lease on land that is later subdivided during the lease term are not shared by the owners of the subdivisions, but belong exclusively to the owner of the land where the producing well is located. For example, if A granted a lease to B, then sold one-half of the land to C, and a well on B's half started producing minerals, only B would be entitled to the royalty.