Convert mineral interest to Working Interest?

I have mineral interest in Lea County, IN SEC 34&35 T17S R37E NMPM Have had offers for 20% royalty for my 8-10 NMA’s. They also are offering to convert it to working interest. I have never heard of this, but wondering which is best for me. I think there is a Matador well 2 miles from me. Is this area worth more than 20%?