LIMITED DEPTH ABRASIVE JET CUTTER

摘要

Tool and method to cut or perforate a pipe positioned partly or wholly inside another pipe and damage to the outer pipe must be avoided. Jet nozzles (124) are positioned at a non-normal angle to the target surface (102) to reduce the jets' effective cutting distance. While pumping the abrasive fluid, the jets are supported at a selected radial distance from the target surface (102) so that within a predetermined operating time the jets will cut or perforate the inner pipe but leave the outer pipe substantially intact. The tool may be rotated with a motor to perfonn cutoff operations or held in a fixed position for perforating.