Tex. Natural Resources Code § 51.251: PARTIAL CONFLICT OF TITLE.

If there is only a partial conflict of title under a patent, the commissioner in the manner provided in Section 51.250 of this code may cancel any patent presented to him and issue a patent to the applicant for the portion of the land that is covered by his original patent but that is not in conflict with the older title if the area can be determined from the field notes.

Acts 1977, 65th Leg., p. 2437, ch. 871, art. I, Sec. 1, eff. Sept. 1, 1977.