Thursday, July 21, 2016

Science & Technology: Jackhammer Design for Geothermal Drilling

Designing a geothermal drilling tool that can take the heat (Sandia National Laboratories)

(Photo by Randy Montoya) 
Sandia National Laboratories and a commercial firm have designed a drilling tool that will withstand the heat of geothermal drilling.

The downhole hammer attaches to the end of a column of drill pipe and cuts through rock with a rapid hammering action similar to that of a jackhammer. Downhole hammers are not new — the oil and gas and mining industries have used them since the 1950s — but the older design, with its reliance on oil-based lubricants, plastic and rubber O-rings, isn’t suited for the hotter temperatures of geothermal drilling.

“The technology behind the new hammer is fundamentally the same, but Sandia worked with Sweden-based Atlas Copco in material selection and dry lubricant technology that will work in the high-temperature environment,” said mechanical engineer Jiann Su, Sandia’s principal investigator on the project with Atlas Copco, which operates worldwide and makes specialized equipment and systems for drilling, mining and construction.

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.