| 摘要 |
FIELD: construction engineering. SUBSTANCE: this can also be used in drilling geological prospecting, hydrogeological, oil and other holes, in bottom hole coverage, etc. Simplified operations and reduced cost of energy and air are achieved as follows. After termination of drilling bore-hole to required depth, thixotropic flushing liquid is left in annular space. Widening is formed by delivery of compressed air through tubes and drill bit which is lifted-lowered within widening range. Flow rate of compressed air delivery is chosen so as to ensure retention of column of flushing thixotropic liquid in annular space. Large-size sludge particles left after forming of widening is removed by flushing liquid even after deepening of bore-hole by drilling. Method is preferable for use when drilling in loose sand. EFFECT: high efficiency. 1 cl, 1 dwg |
