Electric Impulse Technology - Long Run Drilling in Hard Rocks

摘要

The costs for a well drilled in hard rock formations depend significantly on the available drilling technologies. Conventional drill bits are especially adapted to the needs of the oil and gas industry, but provide a limited suitability for crystalline formations. The Electric Impulse Technology offers a promising alternative for this purpose. The splitting effect of electrical explosions inside the rock is used to destroy the rock instead of mechanically working against the compressive strength of the rock. In a project funded by the BMWi (Project Number 0325253), a drill head was developed, which consists of a pulse power source of up to 500 kV and electrodes for a 12 1/4" borehole. The drill head is designed for downhole pressures up to 750 bar and temperatures up to 200 °C. A test stand was set up at the TU Dresden to perform test drillings under simulated borehole conditions. Drilling rates of 1 m/h were verified. For the BMWi supported follow-up project, which started end of 2014, the drill head will be optimized and the power supply will be designed. The total system will be used in a test well and assessed.