WorldWide Drilling Resource

How to Inspect Geothermal Drilling by Peter Tavino Litchfield Geothermal IGSHPA 2.0 is a reorganization of the International Ground Source Heat Pump Association (IGSHPA) under the leadership of Director Bob Ingersoll. IGSHPA 2.0 will be featuring new specialties, including one on inspecting ground loops. Below are some outline ideas for WWDR readers and the IGSHPA Committee charged with pub- lishing it. Woody Allen best said, "Ninety per- cent of success is showing up." Ronald Reagan said, "Trust but ver- ify." Homeowners or business owners who can oversee the drilling work done on their property (themselves or through an agent) enhance their chances of a good job. Competent drilling contractors I inspect, tell me they welcome the over- sight, and wish their competitors were inspected as well. Experienced drilling professionals who take no shortcuts, take pride in explaining and showing off their good workmanship. I do not divulge secret strategies, but I do encourage the drill crew to be efficient and orderly. I might ask why it takes so long to fill a loop with water using an undersized pump hose, for instance. Drilling contractors who encounter problematic rock, learn quickly not to return to the shop and claim they could not insert a loop to its full depth. When they retry and redrill, or add more casing until it is done right, and it is witnessed, it is more fully appreciated. Geothermal inspection should follow the same guidelines as other construction inspection. For years, I checked rebar in skyscrapers before concrete was placed. I also inspected aggregate beneath asphalt, etc. Once set, loops are not observable anymore, except for required pressure drop through total length, so inspection ascertains the loop is correct. Here are tips for the new inspector: Before Drilling Starts • Take photos of the grounds, es- pecially near ornamental plants, and hard surfaces. Confirm the owner agreed to necessary tree cutting and changes to final landscaping. • Bring your hard hat, ear plugs, and the site plan, and check that required separation distances are met. • Be sure the Call Before You Dig utility markers are visible. • Check that the sediment pit and/ or toed-in silt fence for cuttings capture are adequate. Is there a yard or more of storage per 100 feet of 6-inch bore? If they encounter 35 gallons per minute of groundwater, where does it go? Is the pit set to reuse the cuttings as pipe cover if sand is not purchased? Will the final raised grade with extra cuttings vol- ume be okay to the owner for drainage runoff, if cuttings volume is not trucked off-site, or blended into a larger area? • Know where electric power sup- ply, potable water, and restroom facili- ties are. When Rig and Service Truck Arrive • Check the loops for proper diam- eter and stamped length. Don't allow a 1¼-inch 910-foot U-bend in a 1½-inch- diameter specified 500-foot deep bore- hole! • Check how many lengths of 20- foot-long steel casing are on the job, in case you are distracted from confirming how many feet were installed to ledge, at extra cost to your client. • Count how many 20-foot-long 4- inch-diameter rods are on the carousel, storage bin, and service truck. If 25, sub- tract what's left to know the current depth (from 500 feet), instead of constantly asking the drill crew how deep they are. • If you do not know them, ask and write down the drill operator’s and helper’s names. Have them filed for next time they are on another job with you. Be friendly and not annoying. During Drilling • Inspection, once underway, can be tedious. If you can leave while they drill past the casing for a few hours, do so to save your client your fee. If not, don’t keep checking your phone all day. Park your vehicle where you can ob- serve the drilling, and sit inside reading something worthwhile, like WWDR . • Keep alert that drill cuttings and groundwater are not "trespassing". Loop Placement • When final depth is reached, watch the entire buoyant U-bend loop filled with water placed to its full length. As it is cut for water fill, listen for the hissing sound to know it was airtight. • Be sure both ends of the pigtails are heat fuse clamped tight or taped, so no dirt falls inside. • Be sure the loop is secured to the casing, so it will not rise off the bottom. Old-Timer Tips • Do not buy coffee for the workers; there is no need for them to buy for you. • Think "safety", but don’t overstep your responsibility into Occupational Safety & Health Association inspection or beyond your scope of work, especially into contractor matters. While being help- ful is nice, you shouldn’t involve your- self in their work. Speak on important issues with the drilling contractor in charge, not the helper. • Keep a few time-stamped photos to accompany your written progress report for the activity you saw. • Enjoy working outdoors in the fresh air and sunshine, getting good exercise, which you do not get in the office! The statements and comments in this article are based on information and references believed to be true and factual. If you have any questions or comments, please forward them to me in care of WWDR . Pete Peter Tavino may be contacted via e-mail at michele@ worldwidedrillingresource.com 34 JANUARY 2015 WorldWide Drilling Resource ® “To reset efficiency is a mark of inefficiency.” h Henry Ford