Water Well Design

Published On: April 17, 2024By Categories: Drilling, Plan for Success

Part 2. Choosing the drilling method.

By Ron Peterson

In the previous installment of Plan for Success we discussed making sure we had done our homework in preparing to install a water well system, so let’s continue.

We have researched and know as much as possible about the proposed well. We have gathered relevant information, including researching nearby offset wells. We have included in our research what problems were encountered on those available offset wells.

There are many different drilling methods available to us in the industry today. Will we simply take the first rig available? Or will we select the rig that has the greatest capability to successfully complete the well?

Finding the Right Rig

Cable tool rigs, conventional mud rotary, air rotary, conventional flooded reverse, dual tube flooded reverse, casing advance systems, and others are all available. While you can probably successfully drill the well with any one of these, there are advantages to each. If we have options, we should weigh the advantages and carefully select the best drill for the job.

Once we have picked the drilling rig we will use, we can then determine the tooling necessary for the job. This includes auxiliary equipment such as mud pumps, air compressors, drill string, hole stabilization, drilling fluid, drilling fluid maintenance equipment, and so on.

If we use air drilling, will we use conventional air or foam? If foam, will we want to use enhanced or stiff foam?

If we use reverse circulation, we need to remember that reverse circulation is effective at removing cuttings from the hole, and they can be very large. Large cuttings can damage the shaker screens, so we will need to have a way to prevent such damage by having a settling pit ahead of the shaker to let the large cuttings settle out before the fluid is sent to the shaker.

In any case, we also need to be careful not to over-drill our ability to clean the hole and process the fluid to remove the cuttings.

The drilling rig used will be a big factor in determining the proper drilling fluid program to maximize hole stability, minimize formation damage, and maximize well performance.

A successful drilling fluid requires a well-designed, adequate mixing system to ensure that no unyielded drill fluid additives enter the production zone. Unyielded drilling fluid additives can be difficult to remove and may adversely affect the well’s performance.

Designing the Well

Let’s now look at the proposed well design. Did we get enough information, or do we need to wait until we have drilled the well? What is the proposed diameter and depth of the well? If we don’t have enough information—and especially if it is a deep or a large-diameter well—it may be a good idea to drill a smaller test bore.

A smaller-diameter test bore or pilot bore will, while adding a step to the well construction process, have many worthwhile benefits. The test bore will be easier to keep straight than a large-diameter bore and can be used as a pilot bore for the larger final bore.

It will help us identify any potential drilling problems, and allow us at a much lower cost to determine how we can avoid or lessen those problems when drilling the final bore. It will provide us with the opportunity to log the hole, determine the available aquifers, and design the screen and casing needs so that we can have the needed material on hand to complete the well quickly when the final bore is completed.

Once we have a better understanding of the geology that we will encounter in the well, we can then decide on the casing design, the best drilling method, and fine-tune the drilling fluid to use.

If we have options, we should weigh the advantages and carefully select the best drill for the job.

Effective Well Development

What are we going to do for well development? Are we going to just spend the minimum amount of time required or are we going to conduct a planned and effective well development program?

Finally, one of the most important things you need to do involves the client. Make sure you understand their needs and discuss and provide information as appropriate to them.

If you have any concerns or questions on any phase of the project, contact the appropriate vendor to obtain the best information on product application. Make sure you know when and who to call for any type of help. Always have contact information ready and available. Use these personal resources when you need them.

Of course, safety is a necessity. Always be aware of your surroundings. Is there anything that can cause you a problem? Are the surfaces level and clear to walk on? If you are at a worksite, is the area clear of debris? If it is a drilling site, is there any drilling fluid anywhere that may be slick and compromise your footing? Are there any hoses or equipment lying around?

Is everything around us properly secured, and are all the protective guards in place on operating equipment? There are many protocols that if properly followed can ensure we are safe. Make sure they are followed so the goal of a successful water well system can be met.

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If anyone has a question or subject that they would like to see addressed, please contact me either through NGWA or directly at ron.peterson@mountainland.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 ron.peterson@mountainland.com.

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