Lessons on Fluid Drilling

Once you learn the keys to it, fluid drilling can be rewarding and exciting.

By Gary Shawver, MGWC

I have facilitated a class titled “Troubleshooting Drilling Problems” for several years at the Iowa Water Well Association Annual Convention & Tradeshow.

The topics that come up every year are interesting. Recently I did two separate classes, and both wanted to discuss fluid drilling. With that, I thought I should write on some of what was discussed.

Fluid drilling is the least profitable method of rotary drilling. This was documented in a pair of studies done by the National Ground Water Association in the early 1990s when NGWA asked for financial statements from drilling firms across the United States to be submitted anonymously along with an overview of the percentage of work done in the various fields of drilling: cable tool, air rotary, mud rotary, and a few others.

The data clearly showed fluid drilling to be less profitable than air rotary. That being said, if one has a drilling business in an area of heavy overburden or sands and gravels, then one needs to acquire more knowledge and skill sets to deal with the trials of fluid drilling.

When I first got into the business, my father who had been in the business 40 years had just purchased his first rotary two years earlier after doing cable tool drilling the previous 38 years.

He and the crews had no knowledge of fluid drilling. So they drilled all their wells with air rotary the same way they had done cable tool—drilling and driving casing through overburden.

So when I came on, I did this for two years. There were days that were a nightmare and some when I was questioning why I went into the business.

 Going to School

But that second year, my father sent me to a mud school hosted by one of the bentonite suppliers. I was overwhelmed to say the least, but at least I had a starting point to get to the next level.

When I returned home, I fumbled my way through mud drilling. While we completed holes, no one ever looked forward to doing a “mud hole” and we all hoped my dad would give us an “air hole.”

To help meet your professional needs, this column covers skills and competencies found in DACUM charts for drillers and pump installers. DO refers to the drilling chart. The letter and number immediately following is the skill on the chart covered by the column. This column covers: DOD-1, DOE-1, DOE-2, DOE-5, DOE-6, DOE-13, DOL-4 More information on DACUM and the charts are available at www.NGWA.org/Certification and click on “Exam Information.”

I went back to the mud school 10 years later. At the second school, everything began to fall into place. I learned a huge amount, especially since I had been in the field and learned from the school of hard knocks.

Here’s some of the things I learned at that school. Some of this is dated, but it still applies today. You need the right tools for fluid drilling to include, but not be limited to, the following:

  1. Having the right mud pump is key. Today we mostly run centrifugal pumps on holes up to 400 feet. We have modified impellers in some of those and they have been a huge improvement. Duplex piston pumps are used when we go into deep-hole drilling. Flow and pressure are two things one needs to understand when sizing a mud pump.
  2. You need the right type of stabilizers. At the second school, we had an excellent session on stabilizers. The long and the short of it is this: A good, well-built, stiff-winged stabilizer with the wings built all the way down to the top of the bit is key. These help keep the hole not only straight, but help with mud rings in clay and help build wall cake when drilling through sands and gravels.
  3. The right bit is vitally important. For years we have used long carbide button rerun bits when drilling through overburden. The long carbides cut large pieces of clay to help facilitate drilling speed. They also are a godsend when drilling through boulders (as are the winged stabilizers when boulders are encountered).

Steel tooth bits work well for the most part as well, but again bit design is key. Get the right bit for the right formation. PDC bits are coming on strong in the drilling field and I would encourage everyone to talk to your bit supplier about which PDC bit may be right for your applications.

4. The right mud pit or the right mud cleaning system is important. The design and flow through a     pit is critical in cleaning your fluid. Having the right pit volume for the hole size and depth you are drilling is also important.

However, if one is going to do a lot of fluid drilling on a regular basis, I cannot emphasize enough the importance of a good mud-cleaning system. They will not cost you money—they will make you money! They are some of the last pieces of equipment I bought and I can’t imagine drilling a fluid hole today without them.

5. Last, but not least in all this, is your fluid. Building correct fluid for the formation you are drilling through is not only vital—it is extremely important. There are an unbelievable amount of additives you can use today to get your fluid exactly as you need it for the formation you are drilling through.

Learning these additives can be a big chore, but if you learn to use the right additives for the right application—they will make you money, not cost you money!

Going to School Again and Again

In fact, this is where going to a mud supplier’s school is invaluable. But don’t go just once. Go to one every four or five years to keep current and get refreshed on what you may have forgotten. While mud drilling can be overwhelming at times, taking the time to learn the ins and outs of fluid drilling can be rewarding as well as exciting.

Remember: Learning is an ongoing lifetime challenge, and so is drilling with fluids.

Gary Shawver, MGWC, is president of Shawver Well Co. Inc. in Fredericksburg, Iowa. He has been in the water well industry for 40 years and is a Master Groundwater Contractor. He has served as president of the Iowa Water Well Association, the Iowa Groundwater Association, and most recently served on the NGWA Board of Directors. Shawver is semi-retired, having sold his business to his employees. He contributes to NGWA’s member e-publication and can be reached at grs@shawverwell.com.

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