Mining Contract: Development of a Mine Rescue Drilling System
This contract will conduct experiments to improve the efficiency and speed of drilling operations as part of a program related to geothermal wells for energy recovery, and to apply the results to mine rescue drilling.
Contract Status & Impact
This contract is complete. To receive a copy of the final report, send a request to OMSHR@cdc.gov.
This contract was funded as part of an interagency agreement program, which provides a formal means for federal government agencies to share and further technology that could apply to and benefit mine safety and health. OMSHR identifies other government agencies with the knowledge, skills, and abilities relevant to a health and safety gap and works collaboratively with these agencies to identify the type of technology solution desired and to determine specifications for this technology.
Because of the potential benefit to mine worker rescue operations, OMSHR is interested in developing a more mobile and faster means of drilling exploratory and recovery holes to locations where mine personnel may be trapped in the event of an accident. The drilling of such holes gives those on the surface the ability to explore parts of the mine with remote camera systems and provide life-sustaining supplies to trapped personnel. Current commercial drilling systems are generally too large and bulky to be deployed rapidly over a mine location, and it can take several days to mobilize and set up such systems in the typically rugged terrain of a mine environment, which does not include the sizeable access roads or working pads necessary for the drilling and auxiliary equipment.
Sandia National Laboratories has been developing drilling technology for geothermal and fossil energy recovery for over 30 years, and has recently been exploring the development of a compact, mobile, ultra high-speed drilling system for a variety of potential applications. Further development of this technology for mine rescue applications would allow rescue efforts to be far more effective, with the potential for the drilling system to be air-lifted to a location, set up, and drilling a hole into the mine within a matter of hours.
Work completed under this contract led to development of an ultra high-speed drilling system using a specially designed, down-hole drilling hammer. The penetration rate in strong rock formations is dramatic, reaching up to 20 times the rate of normal drilling systems. A key to successful implementation of this system is determining the appropriate drilling parameters (forces, velocities, and compressed air pressures and flows) to drill rapidly in coal-bearing rocks. These rock units vary considerably in unconfined compressive strength, ranging from less than 10,000 psi to upwards of 30,000 psi. This variation impacts drilling rates, and adjustments to the drilling parameters are important to achieve the enhanced drilling performance necessary for mine rescue operations.