Looking at adding a 4-5 acre pond to my place. One of my options would put about 3ft of water over an old plugged oil well. Would be no dirt work in that area. This is in Texas. Bad idea? Avoiding the old oil pad will lose me about 1.25 acre of pond.
How much do you trust the plug? If it's not perfect, you could have stuff seeping into the pond, or water leaking out.
Have you tried to put some water in so you can tell if it leaks?
toledo,
Most states have a public database that shows the year the oil well was drilled and the year that it was plugged. See if you can find that info for the well on your property. (If you send an email to the Texas Railroad Commission and say that you are a landowner with a plugged well on your property, they may be able to send you the info in their database.)
Generally, a well drilled AFTER 1980 and plugged after that time has a very low chance of leaking.
An old well drilled in the 1920s or 30s and plugged in recent times DOES have a small chance of leaking. (An oil well drilled back then and plugged before the 70s has a slightly greater chance of leaking.) Basically, they drilled back then by "chiseling" as deep as they could go, and then pounding in a large diameter steel pipe. They would then drill as deep as they could go on the next round, until they had to drive in the next smaller diameter of steel pipe.
They DID NOT cement these intermediate casing strings during that era. (Because they tried to pull them out of the hole after drilling the well to total depth.) Therefore, the old well could have been "properly" plugged during the modern era with cement down the final string of casing, yet the well could possibly leak down an intermediate string of casing that was never cemented. (That is why that type of oil well construction is no longer permitted.)
Please post again if you can get the well info.
Without more info, I would say it is PROBABLY SAFE to cover that old oil well with pond water.
P.S. There may also be some old pipes around the wellhead than can leak some oil or VERY salty saltwater when you excavate in the area. Generally, those pipes are cut off below "plow depth" and then capped.
Do you know where the tank battery was for this oil well? Generally there is some processing equipment that was set 20-50 feet away from the well, and then a set of tanks that would have been located just inside your fence line at the nearest county road. If you have an excavator on site for your pond build, then I might recommend digging a sump near the oil well. Then do some digging in the direction you think the equipment might have been located.
You may encounter some 2" steel pipe near the well that ran to the nearby production equipment. You may also encounter some 2-3" white PVC pipe that ran over to the tanks by the road.
If you find those types of pipes, I would make sure they have a drain to your sump, and then have the excavator cut those lines. That way any remaining liquids can go into your pit. If you do get some oil and saltwater, then you will need to call an oilfield water hauling company to drain your pit. (They should charge $300 (or less) for that if you are in an area that still has lots of wells pumping.)
If you are positive that there will be no dirt work in the area of the well, then I would probably skip the step of excavating around the old well.
Good luck on your new pond build!
I agree with FishinRod, but I think I would still like to dig around the old wellhead and take a look at the cap. The production casing may not have been pulled so it could have multiple welded caps/wraps. If all casing strings are welded up tight, then very low chance for anything to ever leak. If everything is healthy and green around the well and old tank battery, than more than likely you'll be fine. Plus once you uncover the well you'll have a nice sump to fill with water to check for any gas leaks.
Was this well plugged while you owned the property? I'd say modern P&A jobs were much more sanitary than older ones.
If you post your email address I can contact you directly and help you find the old well record too if needed.
When we dug our 9 acre pond I didnt research well records because I knew they were so old and OKLA doesnt have that great of a database prior to 1970. Luckily we didnt uncover anything.
Properly capped wells these days are cemented at various depths down the pipe string.
As mentioned above here is the Texas RRC page where you can get some information on the well. Open the visibility tab in the top left corner to show wells, pipelines etc. Then drill down on your property.
https://gis.rrc.texas.gov/GISViewer/