In Fain & McGaha v. Biesel, 331 S.W.2d 346, 348 (Tex. Civ. App.--Fort Worth 1960, writ ref'd n.r.e.), the original oil and gas lease for 110 acres authorized the lessee to release any portion of the original lease back to the lessor. Id. at 347-48. The lessee released the north sixty acres but retained the south fifty acres under the original lease. Id. at 347-48. The ORRI (overriding royalty interest) owners argued that because the lease continued on the south fifty acres, any subsequent lease of the north sixty acres would be burdened by their ORRI. Id. at 347. The court rejected their argument. Instead, it reasoned that because the original lease allowed the lessee "at any time to release any portion or portions of the leased premises and be relieved of all obligations as to the acreage surrendered," the ORRI pertaining to the released acreage was necessarily extinguished "unless the instrument creating the overriding or royalty interest as an estate in itself makes express provision to the contrary." Id. at 348.