I’ll bet there are a lot more than 15 heirs. I used to work for a company that was always having to try to clear up these small pieces of land. It’s usually black folks but I was involved with one that had 14 heirs, all white. Since the land is usually only worth a few hundred bucks per “share”, if we got it where there were only a few we couldn’t find, we’d bond around it.
One of the biggest hurdles to get over is when there are a bunch of kids who are heirs. You have to get a judge to approve it and he or she usually wants some money put in a trust fund. Most of the times it’s better to just walk away.
Back in 1946 a man platted out a “subdivision” south of Houston and sold lots. It’s hundreds of acres. Nothing was ever done. The streets were laid out but none were ever built. No utilities, nothing. Now every lot is wooded. Oil companies have been trying for years to buy the lots but they can’t locate owners who are still alive or all their heirs. My cousin owns one lot and they offered her $300. She laughed.
Lots of folks walk away when its a passel of “chillrins (adult)” heirholders. Sometimes Title companies have had to research back to before “Reconstruction” to find unclouded. Still there are horror stories of years later another one popping up “wantin dare parit”.
The oil co. is probably only wanting the minerals. My Ol Granddad told us to never sell your minerals. Even on small mineral holder portions leases usually will get that $300 offer to sign + 15 / 18%.