WorldWide Drilling Resource

New Down Hole Hammer for Geothermal Drilling! Adapted from a Press Release by Sandia National Laboratories Over the past three years, Sandia National Laboratories and Atlas Copco have worked to design a drilling tool capable of withstanding the high temperatures associ- ated with geothermal drilling. Down hole hammers are common in the oil and gas, as well as mining industries. They are attached to the end of a column of drill pipe and cut through rock using a rapid hammering action. Since the 1950s, down hole hammers have used oil-based lubricants and plastic/rubber O-rings, which don’t work well when drilling into hotter temperatures. “The technology behind the new hammer is fundamentally the same, but Sandia worked with Sweden-based Atlas Copco in material selection and dry lubricant technol- ogy that will work in the high-temperature environment,” said Jiann Su, mechanical en- gineer and Sandia’s principal investigator on the project with Atlas Copco. The Department of Energy (DOE) Geothermal Technologies Office funded Atlas Copco as prime contractor on the project, and the company partnered with Sandia as the subcontractor. “Part of what the DOE’s Geothermal Program is looking to do is help lower the cost of getting geothermal energy out to customers,” said Su, a researcher in Sandia’s geothermal research department. “Some of reducing the cost is lowering ex- ploration and development costs, and that’s one of the areas we’re helping to tackle.” Su considers the project a success and said the team andAtlas Copco are looking for opportunities to deploy the tool. “We developed a tool that can be used in high-temperature environments that can help increase the drilling rates and the rate of penetration to maybe five to ten times that of conventional drillingoperations, so that’s abigplus for [drill operators],” he said. “It adds to the available options [they] have. This is not necessarily the final op- tion for every drilling situation, but it does provide a good option for the right situation.” A critical piece of the project was developing coatings, which help reduce friction between parts, important in geothermal operations. As temperatures increase, the oils essentially cook, creating a sooty mess similar to running your car too long without changing the oil. Working with Sandia’s Materials Science and Engineering Center, the team was able to develop a unique multilayer solid lubricant capable of operating at high temperatures. Technologist Elton Wright assists as Jiann Su inspects a down hole hammer used at the HOT test facility. Photo by Randy Montoya. ! " # ! New Down Hole Hammer cont’d on page 46. 29 WorldWide Drilling Resource ® JANUARY 2017