Electric Impulse Technology: Less Energy, Less Drilling Time, Less Round Trips

Abstract

Abstract The paper presents a new drilling technology. With the Electric Impulse Technology it is possible to drill boreholes with less energy demand, more drilling speed and less drill bit changes. Drilling results, calculations und further steps will be presented. The new technology uses high voltage impulses to destroy rock with almost no wearing of the drill bit. Engineering a drill bit with this technology will advance the drilling activity for oil and gas as well as geothermal drilling and mining. The objective is to develop a whole drilling system suitable for a conventional drilling rig. Within the first step an impulse voltage generator including a drill electrode was engineered, tested and evaluated. Drill performance under pressure with OBM was investigated. Next steps will include the developing of the energy supply for the system and field tests. The impulse voltage generator designed as a downhole tool was developed to drill bore holes with a diameter of 12 ¼ inch in hard rock with a drill speed of 1 to 2 m/h which is comparable to conventional drilling bits. Furthermore it withstands temperatures up to 200 °C and pressures of 1000 bar. The components of the generator have a lifetime about 350 h, so a bit could be used almost seven times longer than a conventional drilling bit. In laboratory tests a block of granite was drilled on a length of 50 cm with a diameter of 12 ¼ inch. Additionally further materials like limestone, sandstone, marble and iron ore were successfully destroyed. Pressure tests up to 500 bar with WBM and OBM were performed and analyzed. The whole design process of the generator and the electrodes was accompanied by network analysis and FEM calculation. The paper presents the new results of the development of a drill bit based on the Electric Impulse Technology. After the engineering of the impulse voltage generator and promising results the development of the power supply get into focus. The pressure tests show that the Electric Impulse Technology will work under borehole conditions. In addition to early processing the drill bit will be configured for drilling with WBM concerning environmental and financial issues.