AD, as is common you probably own an undivided interest or a % of a much larger parcel. Meanig that you don't own all of any single acre but a % of all of them. If I had a 10% interest in the 640 gross acres of a section, I would have 64 net acres. If my section were pooled into a 1280 acre 2 section spacing where I had no ownership in the other section, I would still have 64 net acres but my decimal interest would be halved and my royalty would be halved compared to 640 spacing of equal production.
If all you care about is net from gross acres, you can stop here.
Really 640 acre spacings are too large for 4500 to 5,000 ft Bakken well. you could just as easily do it on 320 acres spacing. If someone says "Hey, that 2 section 10,000 ft lateral produces twice as much as a 5,000 ft lateral", you can ask them if it produces 4 times as much, because that is what it would have to do to give more royalty than a 4,500 to 5,000 ft lateral on 320 spacing.
After the initial flush production, many of the 10,000 foot laterals don't compare well on a foot by foot basis with the shorter laterals when the pressure is gone and production depends on a pump. I have found information where it is estimated that 70% of production comes from the first 3/4 mile of lateral wellbore, thats 3960 feet. No wonder so many wellbores in Texas are in the 4500 foot range. (Sarcasm alert) We all know that those Texas operators know very little about producing oil and just haven't yet figured out that the 10,000 foot lateral wellbore is so superior that you wouldn't want to drill anything else.
Operators continue to drill 10,000 foot laterals in areas where the field pressure is nonexistant for practical purposes after only 3 months, and that last mile of lateral does very little considering the cost to drill it and the expensive fracking/completion that was only of use for a very short time. If one looks around for one of the uncommon 3 section, 1920 acre spacings where they drilled from the center 7500 feet each way, their production is as likely to be greater than a 10,000 foot lateral in the same area as it is to be less.
I know you didn'r ask about anything but net acres, but you seemed interested in the behind the scenes of the Bakken play and the overlarge spacings and the inefficient wells of the land grab are the 800 pound gorilla in the room that is seldom talked about.
Is it going to change? No. Is there anything one can do about it? If you aren't held by production or leased, you could refuse to lease and that would make them grind their teeth. They are doing all of this as much to have unproductive acres under lease which is better than owning them. If you won't lease, they are drilling these horribly inefficient and expensive wells to little purpose and they have to pay you a royalty anyway that is not great and not poor, whether you leased or not, and one day you may be part owner in the well. Your mineral acres remain your mineral acres and continue to appreciate. Even leased your mineral acres would appreciate but they are then the lessees appreciating asset and not your appreciating asset.