Polycrystalline diamond compact bits tested for geothermal drilling
In order to cut the cost of geothermal drilling, 30 years ago polycrystalline diamond compact (PDC) bits were developed that are still used for drilling the wells, those provides us nearly two third of the present oil supply. Recently, the technology was brought full circle by the US Navy and Sandia showing how original PDC Technology may be used by geothermal drillers integrating decades of continuous improvements by the gas and oil industry. As a part of geothermal resources evaluation, phase one demonstration tests were conducted by the US Navy’s Geothermal Program Office (USN GPO) and Sandia at the Chocolate Mountains Aerial Gunnery Range in Imperial Valley, California.
The dream of the Department of Energy (DOE) is to access geothermal heat for advanced geothermal development by drilling great depths, up to 30,000 feet. As an experiment a test hole was called by the Navy and Sandia demonstration project so that geothermal resources can be evaluated which would have been untraceable otherwise in Hot Mineral Spa region or camp Billy Machen.
The important aspect of project was to evaluate and test PDC bits and related technologies in the real world drilling environment. Therefore, Sandia worked with National Oilwell Varco (NOV), PDC bit manufacturer of Houston who provided on site experts and drill bits used commercially to drilling contractor while demonstrating drill runs. For more than four days in a well of overall depth of 3,000 feet two bits were drilled 1,291 feet throughout the drilling process at the rate of 30 feet/hour, which was three times better if compared to standard roller bits. Data was collected by the teams afterwards from both the bits for analysis.