WorldWide Drilling Resource

Water-Based Drilling Fluid ~ The Water Phase by John Christ J.C.’s Drilling Consultant Where do you get your water to mix with? Do you have a well at the shop? Is it a public water source? Pumped from a lake or pond? Storm runoff? Once, I was told someone got their water from the fire department in a tanker. Gee, I didn’t know the fire department made their own water! Who knew? Different sources will have slightly differing qualities. Most water well drilling professionals bring their water supply with them. Most horizontal directional drilling (HDD) contractors get theirs from a fire hy- drant (this may be different than fire department mentioned above) or they do like their lakes, ponds, and rivers. I don’t care where your water comes from if you test it to see what you have to start with. A few tests to consider are pH, total hardness, chlorine concentration, and sand content. Yes, there are more you could do, but unless you have a problem, you don’t need to. The first tests should be pH and total hardness. No matter whether you’re making a drilling fluid or a grout, these are im- portant! Do a chlorine test if you can smell it and you’re getting it from a public source. Sand content test if from a waterway, or really any source. If you’re sourcing from a waterway, make sure the suction isn’t on the bottom. I always used to carry panty hose in my truck. Never know when you need to rob a convenience store or put over the end of a suction tube! It’s always good to be prepared . . . until your wife finds your stash. Let’s consider the acidity or alkalinity (pH). Acidity is measured 0-6, with 7 being neutral and 8-14 is the alkalinity side. Drilling fluids and products like a pH of 8.5-9.5. How do you check pH? Well, there are litmus paper, test strips, meters, or titra- tion. I personally like test strips. Caution! Make sure you get the 0-14 strips. Some pool test strips only read acidity. As with any of the other methods, you should use some common sense. After removing a strip from the bottle, use it immediately and make sure you put the top back on the bottle. Moisture in the air can change things. Also, date your bottle when you open it. Strips are good for about six months after opening. Okay, we have a sample of water and a test strip in hand. Go ahead and dip it in the water. There is a chart on the container to match up to get your pH value. Most of the water I checked in the Midwest was between 5 and 7. Sodium carbonate (soda ash) is what we use to raise pH safely. Doesn’t take much, ½-2 pounds per 100 gallons of water. If you’re at a 5, it will probably take a couple pounds or so. A 7 and it could be as little as a ½ pound per 100 gallons. If you are going to drill into cement contamination, you will want to lower pH with bicarbonate of soda. A total hardness test is next. Again, I like strips; they are easy, convenient, and accurate. Use the same as mentioned above. If you are titrating, you are looking for a 6, to be around 100 parts per million. Take your value, say 6, and multiply by 17 and you get 102 parts per million. The main component we are looking for is calcium. We are trying to lower it to 100 parts per million. Not always possible, but it is our target number. Soda ash doesn’t just raise pH, it also helps in removal of calcium. In the Midwest, a good average is 200 parts per million. There is a for- mula of 0.0095 times total hardness in parts per million equals pounds of soda ash per 100 gallons. Example 0.0095 X 200 = 1.9 pounds of soda ash per 100 gallons of water. Remember, water weighs 8.34 pounds per gallon at 70ºF (21ºC) and sea level. So, 100 gallons is 834 pounds. A small amount of soda ash pretreating water will ultimately save time and money. It wi l l help make al l products work as advertised! If your water source is con- stant, you don’t have to test all the time - only if something changes. Quick story, about an HDD job in the New England area. The water in this area was extremely hard, so the town was al ready pretreat ing the water. Drilling contractor was loving it, mud was mixing just as he was told by the manu- facturer of the bentonite. Christ cont’d on page 48. 12 MAY 2017 WorldWide Drilling Resource ®