Process for preparation of perfuracao and device perfuracao for study and exploration of the underground

摘要

PCT No. PCT/FR88/00388 Sec. 371 Date May 10, 1990 Sec. 102(e) Date May 10, 1990 PCT Filed Jul. 24, 1989 PCT Pub. No. WO90/01102 PCT Pub. Date Feb. 8, 1990.The invention relates to the drilling of a hole for the study of the underground. The roto-percussion head acts on the drilling tube of which the base carries a cutter. The cutter is integral with the sleeve inside which drilling water is injected. The water and the rock debris go up and out through the evacuation opening. Application to the reverse flow drilling allowing to extract at the evacuation opening cores or rock debris which go up inside the axial tube as soon as they are taken without any risk of being contaminated by the previously traversed layers of ground.