Welcome to the forum. It is smart to be looking into this before you buy, many folks don’t. You didn’t mention how many acres are involved and where you are in the purchase process, which can make a difference. Ideally the status of surface control is something to ask about before a contract is signed.
Regarding the old leases on Sch. B, ask the title company to email you copies. If they are beyond their primary term and not “held by production” they have expired. If they are beyond their term and the seller has no knowledge of production you can request they sign an Affidavit of Non-Production that will allow the title company to delete them from the commitment.
If you haven’t aready, a starting point would be asking the owner if they own the mineral interest in the property, or if not whether they have surface control. That could be through a waiver of surface use in their acquisition deed or other recorded documents signed by prior owners of the property.
If the person you are buying from does own all or part of the minerals and will be retaining that interest, or they otherwise have surface control of the property, then you’ll want to have waiver provisions included in your acquisition deed.
If they don’t own minerals, have surface control, or knowledge about who controls the minerals and surface use of the property, then researching the chain of title may be required to establish who does. Maybe that can be accomplished through a couple of hours digging in the deed records at the County Clerk’s office. If you are buying a piece of what originally was a larger tract that will make the research harder.
If it turns out the mineral interest got severed from the surface years ago the mineral ownership and related surface control may now be spread between mutiple parties. Determining who has that control and obtaining a recordable waiver of surface use may be the only sure solution.