Method and system for removing drill pipe from a drill string

Abstract

A method for removing drill rod from a drill string of a drilling apparatus, the drilling apparatus further comprising a rock drill, a rod manipulation system including a first mechanical clamping mechanism, and a second mechanical clamping mechanism. The drill string comprises at least a first threaded drill rod and a second threaded drill rod. The method comprises: a) vibrating the drill string (201) when the first threaded drill rod is connected to the rock drill via a first threaded joint to loosen a second threaded joint of the drill string, the second threaded joint engaging the first drill rod and the second drill rod, wherein the second threaded joint comprises a second thread of the second drill rod that engages with a first thread of the first drill rod; b) tightening (202) the first threaded joint; c) unscrewing (203) a first portion of the first thread from the second threaded joint when the rotational pressure of the rock drill is below a first threshold pressure; d) determining (204) that the rotational pressure applied to the drill string by the rock drill is above a second threshold pressure; e) completely unscrewing the first thread from the second threaded joint (208); f) unscrewing (209) the rock drill; and g) removing (210) the first drill rod.

Images