I’m just trying to get a better understanding of how things work in the oil & gas well drilling world.
I know that individual wells have a finite production. But what I don’t know is if once a well has been depleted - is it possible/common to build another well in the same location (maybe at a different layer if the earth?) - or is that area now “sucked dry” so to speak?
The broader question being, once production from a well on one’s land/mineral rights area has run its course, is there the potential to build another well on that same plot of land to get even more oil/gas out of it with a new well, or has that area now been depleted of its resources?
Thanks in advance for clarification on this issue.
Yes, it is common. The zones can be like a stack of pancakes. Usually production starts at the bottom zone then when it’s depleted they pull up hole and produce from the next productive zone.
I know of a 120 acre farm that has production from 5 different zones.
Also a plugged well can later be re-entered (washed down). There are better fracking methods now that can make a previously plugged well profitable, or a deeper depth can be drilled. A re-entry is risky so a lot of companies won’t do it.
Sucked dry is relative. They usually leave quite a bit in the ground. They get a little better at getting it out each year. The learn more about each geologic area with every well.
Hopefully this isn’t answering a simple question with too complicated of an answer. I trimmed back the answer from the long-winded engineer version
It all depends on where you are. How many zones, how thick the “oil” column is, etc. You can definitely drill down and have your well go horizontally in one zone and then come back later and drill another well right above/below that existing well by some depth. Or do them both at once. If the oil column is thin, then you can’t really do multiple layers without the wells fighting each other over the oil. Or having fracks from one zone screw up wells in another zone. So when its thin there are less wells and you kind of need to do it all at once and then you are done.
Let’s assume that you are in Eddy County 25s28e. See cartoon below of southern Eddy County subsurface. Ranging from 6500’ to 11000+’ of depth. In this area the # of potential zones is high as it’s very thick. Most zones are totally independent of each other. Your best zones will be the Wolfcamp AXY, the 2nd Bone Spring, and then deep Wolfcamp (D/E). Avalon, 1st BS, etc are probably economic. 3rd Bone Spring is oftentimes too close the the Wolf AXY to be completed. Green dots are better wells, yellow dots are maybes. Figure all the greens get drilled, some of the yellows. Things change though. The Hoss wells being drilled are unlikely to be the last wells drilled here. But it may be a while until they come back.
But in general I would expect to have 18-28 wells per mile wide unit in 25s28e before things are sucked dry. And like r-w-kennedy says, “sucked” dry in this nanodarcy rock means 5-10% of the oil in place recovered.
So I guess the ultimate moral of the story is never assume the resources in your mineral rights have been depleted, no matter how many wells have already been drilled on them. Future technology could easily find ways to extract more value. That was ultimately my bigger-bigger question. Thanks again to the helpful members of this forum, I really appreciate it!
