Remember you do not own the actual minerals until they are produced and reduced to possesion, you own the right to explore and produce the mineral beneath your land. When you lease, you give up your right to explore and produce the minerals beneath your land in exchange for a royalty in any such operations.
The lease will still be in effect and any sale will be subject to it with or without production so long as the lease is still valid, i.e. still in primary term, HBP, shut in well with rentals paid. Also the new owner would be held to any renewal clause in the lease, and would receive that renewal if the leaseholder decides to exersise that option.
My comments apply to LA. I am not knowlegeable enought to comment on TX, but I do not see how it should matter. The minerals would be conveyed if there is no reservation.
If the Seller owns 100% on the mineral rights, sells with no resevation in the deed, the buyer will be conveyed all of the sellers rights, which in this example would be 100% of all the mineral right on the tract.
The same would apply in La, only you would have to see if they prescribed back yet. I assumed that this was a simple example, but in the real world it is seldom simple.
I may not be an expert, but here goes. if you owned a well(or portion) in production and made no reservations during the sale this is what happens. As long as production goes on you will retain the ownership of said production. If production ends, you will then own it for ten year at the end of production. if during that ten years, another well is drilled and begins production, then your ownership continues from them on until the loop happens again. You can check with a lawyer, but i think that you will find this statement correct. If this really happened and you need to talk to me my cell is 294 2384
s.j.