Installation of Well Screens and Gravel Packs

The quickest and easiest way to finish a well is to simply put a well screen at the bottom.  Go to the bottom of this page for an example of how to install a well screen by itself.  Most wells have no gravel pack.  They just have a well screen at the bottom of the well.  I'd suggest you first try a well screen by itself.  98% of all wells simply have a well screen at the bottom with no gravel pack and they work just fine.

I'm hearing from some folks who have tried gravel packs on their first well.  Forgive me for being redundant, but I'm going to repeat this.  Don't try a gravel pack first!  Just use a wellscreen.  It is likely that it will work just fine!

First, drill the hole to the depth you are going to, typically 25 to 35 feet.  Then work the pipe up and down and side to side for quite a while so you have created a wide spot in the hole at the bottom of the well.

Next pour pea gravel down the two inch pipe.

Then, work the pipe up and down as you continue to pour gravel in slowly until the pipe comes up about three feet.  The pipe will not go down through the gravel so you can tell how much gravel you have at the bottom of the hole by how much higher the pipe is than when you started.

The video below shows the installation of a gravel pack similar to the one described just above.

INSTALLING GRAVEL PACK

What you see above will work because the gravel pack itself acts as a screen.  If you are in really soft sand at this point, you may want to install a well screen in the gravel pack.   To do this, push a 1 1/4 inch well screen attached to enough 1 1/4 inch pipe down through the two inch pipe to reach the bottom of the well.   The well screen will look something like these:

I have exaggerated the size of the well screen point in the diagrams below.  It is really the same diameter as the pipe as shown in the above  photograph.  When you reach the gravel pack with the well screen, simply apply constant downward pressure as you twist the well screen back and forth.  If you are in soft sand, at first it will advance quickly into the pea gravel.  It will slow up as more of the well screen goes into the gravel.  When you get three feet of the well screen into the pea gravel, stop.  

If you can't work the well screen into the gravel pack at all, don't worry because the gravel pack itself will act as a well screen.  Just take a 1.25 inch piece of PVC and drill some 3/8 inch holes in the bottom foot to let water in.  Then put it all the way to the bottom so it is resting on the gravel pack.

Pull up or cut off the two inch pipe (be careful not to cut the 1 1/4 inch pipe inside!) and you are done.  In the diagram below, the well screen is shaded yellow, except for the point which is blue.

MOST COMMON AND RECOMMENDED METHOD

I've saved the easiest and the most common for last.  What most folks do is simply put a 1 1/4 inch well screen, three feet in length, down through the two inch drill pipe and then pull the the two inch pipe up as far as you can to expose the screen at the bottom - at least ten feet.  Better yet, take it out of the ground.  You can use it again.  The important thing is to expose the well screen at the bottom of the well.   The sand at the bottom of the hole will collapse around the well screen but this is not a problem.  It will work just fine as long as it is in sand (not clay) and way below the static water level.  The further it is below the static water level, the better.