DEVICE FOR TREATMENT OF BOTTOMHOLE FORMATION ZONE Russian patent published in 2003 - IPC

FIELD: oil producing industry, particularly, devices designed for pulse-vacuum treatment of bottomhole formation zones for increase of well productivity. SUBSTANCE: device has body in form of cylindrical sleeve closed from end. Said sleeve accommodates reciprocating plunger and pressure valve. Body has windows for bypassing of fluid from annular space to device inside. Annular slotted clearance between plunger external surface and body internal surface exceeds 0.2 mm. Upper and lower parts of plunger are provided with one seal each. Said seal consists of rings spring-loaded with flexible holder fitted on plunger. Each ring has part in form of sector whose sealing surface is cylindrical with radius equaling radius of body internal surface. Ring remaining part has shape providing for presence of slotted clearance between ring and body internal surface. Neighboring rings are turned relative to one another so that angle between their radial planes passing through middles of sectors amount up to 360/n, where n is number of rings. EFFECT: higher operate reliability of device and increased well productivity. 2 cl, 2 dwg