METHOD FOR ELECTRIC-PULSE DRILLING OF WELLS, AND DRILLING UNIT Russian patent published in 1998 - IPC

FIELD: this relates to drilling of bore-holes. SUBSTANCE: realization of electric-pulse drilling method implies selection of optimal parameters of drilling mode of operation with taking into consideration working voltage, pulse energy, and flow rate of flushing liquid. Drilling unit is made in the form of source of high-voltage pulses, flushing system, round trip mechanism, and drilling tool. Part of components of drill pipe string is coated with high-conducting material. Drill pipe string is connected with surface pipe through sliding contact. Drilling unit is provided with component intended for selection of optimal modes of parameters. Source of electric pulses is made in the form of inductive accumulator with semiconductor switchgear. High-voltage input is connected to side of drill pipe string. Parts of its components are made with semiconductor coating. Longitudinal slots of removable sludge collector are provided with resilient protrusions. Drilling head-piece is adapted for possible limited turning. Electrode system of drilling head-piece is made in the form of four-electrode cell or in the form of two electrodes with bent ends. Application of aforesaid drilling method and drilling unit allows for improving drilling efficiency due to reliable functioning of drilling tool and also due to timely removal of drilling waste from bottom-hole of well. EFFECT: higher efficiency. 9 cl, 9 dwg, 2 tbl