DEVICE FOR REPAIR OF CASED-THROUGH WELLS Russian patent published in 1995 - IPC

FIELD: oil and gas industry. SUBSTANCE: for more reliable cut-off in the case of abnormally low or high pressure in the bed, the device has a dummy plug with its body having longitudinally corrugated and cylindrical parts. This dummy plug is provided with a spherical dummy plug. The latter is butted with the lower cylindrical part of the body. The thickness of the dummy plug may increase from the edges toward its center, and the dummy plug surface may have radial stiffness ribs or radial grooves. The device may be provided with a spherical insert fabricated from some readily drillable material such as aluminum. This insert may be mounted on pins in the dummy plug. EFFECT: higher reliability. 5 cl, 8 dwg