PROCEDURE FOR FIXING WELL WITH CEMENT GROUT Russian patent published in 2010 - IPC E21B33/138 

FIELD: gas-and-oil industry.

SUBSTANCE: procedure for fixing well with cement grout consists in successive pumping washing spacer fluid and three portions of cement grout. As the first and the second portions of cement grout there is used cement grout of 1650-1750 kg/m³ density with erosion properties containing mixture of back-filling Portland cement and abrasive material as quartz fine dispersed sand with average grain dimension not over 1 mm in weight ratio from 100:8 to 100:10, and also poly-vinyl-spirit PVS -VR at amount of 0.4-0.6% and de-foaming agent at amount of 0.04-0.06% by cement weight. As the third portion there is used the said cement grout additionally containing calcium chloride at amount of 2% and sodium chloride at amount of 1% by cement weight of not less, than 1850 kg/m³ density.

EFFECT: raised quality of formation isolation and increased efficiency of clay coating removal.

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