CASING COLUMN CEMENTATION METHOD AND DEVICE FOR REALIZATION THEREOF Russian patent published in 2007 - IPC E21B33/14 

FIELD: well drilling technologies.

SUBSTANCE: in accordance to method casing column is lowered into well and cemented in suspended position and stretched state. Stretching load is created on lower end of casing column in the moment when its cementation ends due to pressure drop between inter-column and behind-column spaces at depth where stop-ring is positioned and following anchoring of casing column before perforation zone, at level where stop ring is positioned and above perforation zone beyond well walls by means of hydro-mechanical localizing anchors. Device contains shoe, shoe branch pipe, reverse valve, stop ring, signal ring, casing column with, mounted on it, turbulence promoters, spring or rigid localizers, cementing head with mounted cementing plug. Device is provided with not less than two hydro-mechanical localizing anchors, lower one of which is located below perforation zone, at the level of reverse valve, while other hydro-mechanical localizer anchors are mounted above perforation zone of casing column. Value of pressure drop needed for activation of hydro-mechanical localizing anchors is greater than value of pressure drop between hollows inside and outside column at depth where stop ring is positioned in the moment of "stop" pressure.

EFFECT: increased quality of fastening of well walls.

2 cl, 2 dwg