Yes, there are limits. Limits by: geology/technology (frack-worthy rock, number of horizons with potential), regulatory (oil vs. gas, spacing, proration/allocation), leasehold (divided vs undivided, leased vs unleased, operator’s willingness & drilling program), capital (is it economical), and the list goes on. It’s a pretty complex question.
As a quick answer, you’d be hard pressed to see more than 5 or 6 horizontal wells per horizon and across a section. But again, it’s a loaded question with a lot of moving parts.