METHOD FOR EXTRACTION OF FILTER FROM WELL IN PARTS, AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2013 - IPC E21B31/00 

FIELD: oil and gas industry.

SUBSTANCE: before the beginning of filter lifting, it is divided into several parts by means of anodic dissolution of filter metal. Then, each part is lifted in turn to day surface with a lowered pipe string. Device includes housing (1) made from dielectric material, which has flat shape on upper end and conical shape from below and a groove on side surface along the perimetre for arrangement in it of membrane (3) from elastic material, which provides attachment to it of a cathode in the form of elastic split-type metal ring (5) connected with electric wire (13) to negative pole of a direct current source on day surface. An anode is represented with filter (2) divided into parts, the inner surface of which contacts centralisers (10). Coiled tubing pipe (11) is screwed with its end on nozzle (12), provides supply of electrolyte from surface to a filter metal dissolution surface and connected to the current source positive pole. The housing has axial hole (8), in which a nozzle is screwed on the end. The same hole is connected to the membrane cavity. An electric wire attaching a cathode to negative pole of the current source on the surface is laid in holes. Fan-shaped channels (9) are branched off longitudinal axial hole, inclined in upward direction to side surface and taken out of the housing above the membrane; electrolyte is supplied to the anodic dissolution zone via them.

EFFECT: improving filter extraction reliability.

2 cl, 7 dwg