Answering questions prior to getting on site will save on time and surprises.
By Ronald B. Peterson
Once a location has been decided for a new water well system, the next step is designing the well.
This includes doing things such as research on other wells that have been drilled reasonably close by and finding out about the geology that will likely be encountered.
Also included are answering questions such as: Where will we hit water and in what quantities? Will it be artesian? And will we encounter loss of circulation?
The more we know about the potential well, the fewer problems we will have and our potential for success will increase exponentially.
Fortunately, today we have a lot of information about other wells drilled in the area of our jobsite. Let’s use that to our advantage. Of course, you will still encounter the water well that is located in an area with little, if any, background information from time to time.
If this is the case for you, I suggest drilling a smaller-diameter test hole to find out what you are going to encounter. This takes a little longer but will help reduce the magnitude of problems that you may encounter and will substantially increase the potential for a successful water well.
What types of formations will we be drilling in? Alluvial, shales, clays, unconsolidated gravels and cobbles? Cemented gravels? Broken, fractured, or solid rock? This is all the information that we can obtain from previous wells or from a pilot hole.
Finding the Right Method
Once we have a better understanding of the geology, we can then decide the casing design, best drilling method, and drilling fluid to use.
Some time ago I was sitting in the breakfast area of the Holiday Inn Express in Elko, Nevada, and there was a gentleman sitting at a table close by calling in his morning report to the home office.
I didn’t mean to eavesdrop, but he was a little agitated due to some problems his crew was having on the project, and the conversations were quite loud.
I was somewhat familiar with drilling in the area, and when he finished, I asked if he was drilling in Pine Valley. He replied that he was, so I asked if he was drilling down in the valley or up on the mountain. He replied that his team was on the mountain. I immediately had a good idea where he was as I had observed such activity in the area.
I then asked him what the target depth of the hole was. He told me 12,500 feet and that they wanted to set 6-inch casing at total depth. I asked what size surface pipe they had set and was told 24-inch.
Again, I was aware of the nature of the geology in the area and the potential for lost returns. I suggested that they were probably not going to make it to total depth due to the potential issues they would encounter during the drilling process and the number of times they would have to reduce the hole to achieve total depth.
My breakfast companion’s eyes were wide with realization of the situation he had on his hands. He replied that was the conclusion he was coming to as well. They had already reduced twice and were only at 5000 feet. At the end of the day, more information is almost always better than not enough.
Creating a Plan
Drilling a water well is like many things in life. There is an ideal plan, and then there is the one that we will use on the project, based on timing and availability. In the drilling industry, we tend to spend a great deal of time in the real world. We don’t always have the privilege of having everything perfect.
Once we have done our thorough research and have a good idea of what we are going to encounter, we can start to plan the best way to deal with potential problems.
Technology and advancements in drilling equipment, drilling tools, and drilling supplies have come a long way. What type of drill are we going to use? How deep does the surface casing need to be? Will we need to set intermediate casing? What will we use for the screen and final casing? What will we need for a gravel pack? How will we seal the annulus?
Take the time to make sure that you have considered all risks and potential problems.
I would rather be looking at it than looking for it. Make sure that you have everything you will need on location or that you know where it is and can get it quickly if and when you need it. Many problems only become larger if the solution is not readily available.
If anyone has a question or subject that they would like to see addressed, please contact me either through NGWA or directly at email@example.com.
Ronald B. Peterson has been involved with the drilling industry for more than 40 years. He previously worked for Baroid Industrial Drilling Products and is now with Mountainland Supply Co., a supply company in Orem, Utah. He served as The Groundwater Foundation’s McEllhiney Lecturer in 2015 and was given NGWA’s most prestigious award, the 2013 Ross L. Oliver Award. He can be reached at firstname.lastname@example.org.