Project Started for the Development of a Hydraulic Down-The-Hole Hammer

At the beginning of the year DGMK project 733 "Development of alternative drive concepts for down-the-hole hammers in deep drilling" entered its third project phase. In the next three years the prototype for a hydraulic hammer drill is to be developed, manufactured, and tested. The development of the novel drill drive was already started during phase 2 of the project. The existing design is to be revised prior to production based on the experience with the electromagnetic hammer drill from last year.

The researchers around Prof. Dr.-Ing. Matthias Reich from the Institute for Drilling Engineering and Fluid Mining at the TU Bergakademie Freiberg expect that the prototype could be available for the first tests in spring 2020. Compared to the tests with the electromagnetic hammer drill carried out so far, the hydraulic hammer drill is also to be used in a borehole in hard rock.

The application principle of a down-the-hole hammer drill is the same as for a standard domestic hammer drill: while a normal drill in hard ground, such as concrete, hardly achieves any drilling progress and causes high wear of the drills used, this does not pose a major challenge for a hammer drill with impact function.

The greatest difficulty for the development of a down-the-hole hammer drill is the generation of impact energy in a borehole filled with drilling mud that is one to several kilometers deep. In previous project phases, researchers at TU Freiberg had tested and evaluated different drive concepts for this purpose and selected the two most promising ones - the electromagnetically and hydraulically operated hammer drill - for prototype development.

The project is funded by DEA Deutsche Erdoel AG, ExxonMobil Production Deutschland GmbH, Neptune Energy Deutschland GmbH and Wintershall Holding GmbH.