WorldWide Drilling Resource

17 WorldWide Drilling Resource ® MARCH 2015 Drilling Fluid Updates by Ray McLarty Drilling Fluids & Grouts Questions & Answers Question Howmuch soda ash is recommended to treat calcium hardness in mix water? Answer Usually 0.5 to 2 pounds per 100 gal- lons of mix water is sufficient. However, you should always test the hardness of the water before and after adding the soda ash to be sure you have a pH of 8.5 to 9. You can purchase pH strips from local water well supply houses and pool supply outlets. They are inexpen- sive, easy to use, and easy to read. Test the water pH, then add your soda ash, then check it again to be sure the pH is where you want it. If not, continue to add soda ash until you get the desired pH. Question We think we got some bad prod- uct. It was liquid polymer we have used in the past when drilling in clay forma- tions. It did not want to mix. It got all slimy and you could see the unmixed polymer floating on top of the mud pit. The product was not very old and, again, we had used it successfully in the past. Do you think it could have been a bad product? If not, what do you think the problem was? Answer I think one of three things caused the problem you encountered: 1. You got an inferior or bad prod- uct. I doubt it was this. The product you were using has been around a long time. I have seen it used successfully as a clay and shale hydration inhibitor, drilling mud viscosifier, as a two-step mix with ben- tonite to form a grout, etc. I have never seen it fail to perform as advertised or expected. 2. The product was compromised by changes, such as freezing. Was the product on the rig, or stored in an un- heated warehouse or shop? Could it have frozen and thawed, possibly more than once prior to use? Freezing can and will affect a liquid polymer’s yield and performance, and it often results in solidification of the liquid polymer on the bottom of the pail with an oily liquid on top. The liquid on top of the pail would most likely be a carrying agent, and the solid material on the bottom would be the active ingredients which had fallen out of suspension and solidified. 3. The mix water! Did you check the pH of the mix water prior to mixing? I have seen very low pH mix water waste a lot of high-yield polymer, such as EZ-MUD ® , as well as numerous bags of high-yield bentonite drilling mud, such as QUIK-GEL ® . I was called to a jobsite in West Tennessee a few years back where the water pH was extremely low. Before I arrived, the contractor had gotten virtu- ally zero yield out of several bags of bentonite, so he added several gallons of a liquid polymer similar to EZ-MUD ® . The Marsh funnel indicated the polymer and the bentonite never mixed. The Marsh funnel viscosity of the drilling fluid was 28; water is 26, so it was obvious the polymer and the bentonite had not mixed. The liquid polymer was floating in white globs on top of the water in the mud pit. A small amount of soda ash added to the mix water would have prevented this problem, and it did, in fact, solve the problem when added to the mix water. After calculating the cost of the total product used (wasted) before the addition of the soda ash, and how much the soda ash cost, we determined he had saved a couple of dollars by not treating the mix water with soda ash prior to mixing, but he spent over $100 on wasted polymer and wasted high- yield bentonite drilling mud. Spending an additional $100 on drilling fluid to save $2 in a cheap water treatment additive is not good business. Note: EZ-MUD ® and QUIK-GEL ® are Baroid IDP products. Similar prod- ucts would be CETCO ® ACCU-VIS ® and SUPER GEL-X ® , Wyo-Ben WYO-VIS ® and EXTRA HIGH YIELD™ , or M-I SWACO POLY-PLUS and MAX GEL . The statements and comments in this article are my own and are based on information and references believed to be true and factual. If you have a question or comment on this article, or on bentonite drilling muds, polymers, grouts, or additives, please forward them to me in care of WWDR . Ray michele@ worldwidedrillingresource.com