DEVICE FOR COLMATAGE OF WELL WALLS Russian patent published in 1994 - IPC

FIELD: establishment of low- permeable protective colmatage layer in borehole zone permeable layer. SUBSTANCE: device has body made of radial attachments in which plugs in form of hollow cylinders are installed for moving along radial attachments axis. Plug hollow cylinders are filled with solid colmatant. Hollow cylinders are connected with body by spring-loaded retainers located at outlet of radial attachments. Plugs have outer conical recesses on the side of nonworking surface to receive spring-loaded retainers. Body has additional radial attachments located at different levels. They also accommodate plugs and solid colmatant. Body has hydraulic channels between main and additional attachments. These channels are made for alternate placing to working position of plugs. In so doing, plugs of subsequent level are placed in working position after plugs of preceding level are moved to extreme locked position. EFFECT: higher efficiency. 5 dwg