WorldWide Drilling Resource

21 WorldWide Drilling Resource ® DECEMBER 2013 Drilling Fluid Updates by Ray McLarty Drilling Fluids & Grouts Questions & Answers Question We have some wells to drill which specify the mixing and pumping of high- solids bentonite grout in the top 25-30 feet. Rather than mixing a grout, we asked to use HOLEPLUG ® or BENSEAL ® . This is what we most often use. The engineer- ing company asked us to provide them with information on what choices they have in the solids content of a grout and also what the solids content of the dry material would be after hydration and set, versus that of the high-solids grouts. Answer The solids content of dry bentonite materials after hydration averages 60- 70%. Dry bentonite sealing material comes in three basic shapes and sizes. Examples are BENSEAL ® , an 8-mesh granular bentonite; HOLEPLUG ® , a naturally-occurring gravel-like consis- tency product that ranges in size from 3/8-inch to 3/4-inch; and compressed BENTONITE PELLETS that range in size from 1/4-inch, 3/8-inch, and 1/2-inch. The larger the material, the deeper it can be placed in the well, provided there is sufficient annular space for the material to fall through. The smaller-sized BENSEAL ® and other similar granular materials hydrate rapidly when coming in contact with water. Therefore, it is difficult, if not impossible, to place it in a well through standing water. HOLEPLUG ® and BENTONITE PELLETS can be placed through stand- ing water to depths in excess of 200 feet. My personal dry product of choice would be HOLEPLUG ® or an equivalent prod- uct. It eliminates the need for grouting equipment, “rip it and pour it”. It can be placed at a fairly deep depth in the hole through standing water. The cost of a 50-pound bag of HOLEPLUG ® in my area is $9.50-$10.00. BENTONITE PELLETS cost in excess of $40.00 per 50-pound pail. There are numerous types of ben- tonite grouts on the market today. They range in solids content from 15-40% and higher. Here are four examples of high- solids bentonite grouts: 1.) BENSEAL ® /EZ-MUD ® - This is the original high-solids (20%) bentonite grout that has been around for years. It is a two-step grout that combines two widely used products, BENSEAL ® GRANULAR and EZ-MUD ® LIQUID POLYMER . When the proper amounts of these two are added to 24 gallons of mix water, they provide a simple, economi- cal method to seal and grout the well. 2.) EZ-SEAL ® and 3.) AQUAGUARD ® - These two pro- ducts are single-sack (one-step) benton- ite grouts that have a 20% and a 30% solids content, respectively. Grouts with 20% and 30% solids traditionally require using specific equipment, such as a com- mercial grouter, to mix and place the grout. 4.) BAROTHERM ® SPECIAL - This is an extremely easy-to-mix, easy-to- pump, one-step thermally-conductive grout that yields a solids content of 47%. The product is user friendly and can be mixed and pumped with standard pump- ing equipment available on most drill rigs. It was originally designed to grout hori- zontal or vertical boreholes containing ground source heat pumps/loops. The above products are just a few of the available bentonite-based grouts and/or sealants on the market today. Cross-reference products in the order of those 1.) through 4.) listed above can be found on the chart. Note: Successful placement of any dry material is dependent on the size of the annular space between the pipe and sidewall of the well, and the depth of the water in the hole. 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 admin@ worldwidedrillingresource.com Cross-reference chart for items 1.) through 4.) listed above. ~ The Centerline 7 1/2” x 10” hydraulic drive duplex mud pump ~ Fits in the place of a common 5” x 6” duplex ~ weighs 1000 lbs less ~ pumps twice the rated flow~at over twice the rated pressure ~ Centerline Manufacturing Co. 903-725-6978 ~ www.centerlinemanufacturing.com ~ Mud pumps for the 21st century ~ Monopumps models rated: 180 gpm Duplex models rated: 300 gpm Triplex models rated: 450 gpm 500 or 800 psi models available in aluminum or iron. U.S. Pat. #6,769,884 and others pending ~ Centerline mud pumps are getting the job done from Canada to Australia, China to Peru ~ Centerline Manufacturing is proud to be your complete stocking source for American Manufacturing mud pump parts!!