If you are a regular reader of this column, you know that I have recently written about methods to develop well screens or at least the formations that surround them. I thought I had about covered every popular method ever used, at least in my neck of the woods, and I intended to start a series of columns on pressure tanks with this chapter. However, I recently got a call from a retired well drilling contractor who is my best friend in our industry. He, like me, ran a one-man operation drilling primarily 4-inch wells, with some smaller diameter wells and pump work mixed in. He had a great reputation as a professional in his neck of the woods, which is across the state from where I operate.
Now, this fellow and I have kept in touch over a period of about 50 years just talking about our industry and our own lives. One valued service he provides me is to carefully read each and every column that I write in National Driller and point out any errors or omissions that I have made—for this I thank him. He knows who he is, but I will not use his name here as a matter of privacy. Well, my friend called me recently and said he had read my most recent article and I had missed an important screen and aquifer development method that he and other drillers in his area had used for years. He was right. So, here goes the description of one more way to develop a water well drilled in sand and gravel.
Veteran driller and columnist John Schmitt says some development methods will work great in some formations but fail miserably in others. Source: iStock
I believe this method would only work on 2-, 3- or 4-inch wells due to the parts you need to use the method. Many wells of this size are test pumped with a bremer check set on top of the well screen and a plunger of the proper size attached to either drop pipe or, in the case of cable tools, the tool string itself with the bit removed. I have to say, this is a very effective method of test pumping a well, one that I used in the vast majority of wells that I have ever drilled. A manufacturer in Michigan even makes a combination pumping tool using a check with no rubber to expand, but rather a tapered end that will fit tightly into the top of a well screen or extension or riser pipe. The plunger and valve are connected with a slide mechanism that allows the plunger to run its normal stroke from approximately 18 inches to perhaps 36 inches, and allow the check to remain in place. This unit can be installed for pumping and removed as a single assembly, saving time from using a separate check and plunger.
In using this method, the flow into the screen and, of course, through the aquifer is in-and-stop, in-and-stop as there is no flow on the down stroke of the plunger. I always thought this resulted in some development, as the flow of water was not steady and this likely loosened the grains of sand and gravel that could be wedged due to a steady inward flow into the screen.
I have no proof that this is what happened, but I had pretty good success over the years pumping this way and very, very few wells that ever pumped any sand after they were cleaned up by the check-valve-plunger method.
Drilling the Check Valve
My friend and his buddies took this one step further and drilled a small hole or holes in the poppet of the check valve. The poppet, of course, closes on the down stroke of the plunger, holding the water above and below it. So, with a drilled poppet, you would get some backflow and the back-and-forth motion of that water would impart to the sand and gravel the same motion, which is exactly what we try to do in developing the formation. Now, these holes could be plugged back up if they were tapped to take a machine screw or perhaps an 1⁄8-inch IPS plug. As I recall, my friend said some drillers drilled and tapped several holes and these could be left open or closed to control the amount of backflow desired. I believe to clear the well up for final production, one would have to remove the check and plug the holes to stop the backwash effect. However, never having used the method, I don’t know this for sure.
From his description, I can see where my friend’s method could be quite effective. In 2-inch wells, we usually left a bremer check permanently installed on top of the screen so the backwash check would have to be replaced with the regular version and we could pump the well clear. In a 3-inch or 4-inch well, we would remove the check as a matter of completing construction. I have never seen a bremer check or plunger for a 5-inch or 6-inch cased well, or leathers for that size. I do believe these could be manufactured, and for either of these larger wells, one would want a pretty hefty machine running the plunger, especially in the 6-inch size. You’re really going to be “horsing” a lot of water out of the well in a hurry—if the aquifer will produce it.
No One Way to Develop Screen
This is a method I have personally never used, but it sounds effective and, as I have said many times in these columns, if it works for somebody else — more power to them. Hoping I haven’t forgotten more methods that you, loyal readers, will remind me of, I now come to the end of this subject. And a final thought: I would have to say I don’t believe any single method of screen development will be successful in every last instance. Some methods are going to work great in some formations and be a miserable failure in others. That is why folks hire us to do the best job that can be done and make that well as efficient as possible.
In my monthly weather report, you fellows in the warm weather areas or where it has been extra dry should really be thankful you are where you are. As I write this near the end of February, I can report we have had the second most snowfall in my area of Michigan, that is, since records have been kept dating back to the 19th century. It has also been bitterly cold and I understand we have as much as 36 inches of frost in the ground. I have been blowing snow with a 4-foot cut tractor-mounted snow blower for the last month, and am frankly sick of it—I don’t need any more practice. I blew the day before yesterday and we had anywhere from 3 to 15 inches, depending on the drifting. Today, we are getting rain and freezing rain, although we had a short, fierce snow storm this morning. This all makes Florida, Texas and Arizona sound pretty good. Work hard, work safe and thank God for every day you have on this Earth.
For more John Schmitt columns, visit www.nationaldriller.com/schmitt.