WELL STRING BORING MACHINE Russian patent published in 2010 - IPC E21B29/02 E21B43/25 

FIELD: oil and gas production.

SUBSTANCE: invention refers to oil and gas recovery, particularly - to a machine for removing a segment of a well string by electrochemical treatment. The well string boring machine accommodates a direct current power supply, electrodes, an electrolyte tank, a pipe valve for electrolyte injection, a dielectric pipe to inject electrolyte into the anodic dissolution zone and to sink a cathode cable. An anode is presented with the pipes, while a cathode is a special electrode connected within the removed pipe segment. The electrolyte is a conductor and during anodic dissolution, it is found in a zone of the cathode from any height. The cathode is shaped after the removed pipe segment. The cathode height is equal to the length of the removed pipe segment.

EFFECT: cutting time and reduced cost of removing the required pipe segment by metal anodic dissolution.

1 dwg