PROCEDURE FOR PLACEMENT OF CEMENT BRIDGING IN WELL Russian patent published in 2011 - IPC E21B33/16 

FIELD: gas and oil production.

SUBSTANCE: according to procedure shoe on production string - PS-is lowered into well to lower border of cement bridging. Before lowering into the well a branch with radial orifices is set between the PS and the shoe. Above the orifices the branch has a circular groove with a circular restriction, while below the branch is equipped with a seat of internal diametre less, than internal diametre of the circular restriction. A squeezing plug with a fixing head is set between the cement grout and forcing liquid. The fixing head is set in the circular groove of the circular restriction upon cement grout pumping into annular space. Further, the branch is lifted on the PS to an upper border of the cement bridge. There is created excessive pressure sufficient for forcing the squeezing plug through the circular restriction and for setting it in the seat with branch radial channels opening. Excesses of cement grout are washed off through these channels.

EFFECT: elimination of dilution of cement grout due to pressure tight shutting off tubular space in PS at branch lifting to upper border of cement bridging.

2 dwg