Definitely a job for an oil/gas Landman and/or oil/gas lawyer.  I absolutely do not get involved in oil/gas while doing mortgage work of any kind.  I have searched oil/gas in three states, but make it clear with a blanket disclaimer that oil/gas/minerals have NOT been searched.  I've also explained to title companies that just because there's a lease on property doesn't mean that the surface owners actually own the rights because oil companies will blanket an area and not actually do the title search until later...  It happens all the time (especially in PA where "once severed/always severed" unless deeded back to the surface owner).

I'm a bit confused about the questions you've raised because with the five years up, everything APPEARS to convert.  BUT it will depend on what state you're talking about.

Again, this is a job for someone expert in the field because this means big, big bucks.

I've said it many times before here:  unless you are a Landman, DON'T get involved in oil/gas/minerals.  Mortgage work and oil/gas work are apples and oranges.  They're both fruits, but there are different rules involved -- and different varieties of apples!