METHOD OF CEMENTING OF WELLS Russian patent published in 2008 - IPC E21B33/14 

FIELD: mining.

SUBSTANCE: method includes lowering casing pipe into well, bottom hole flushing, pumping of spacer fluid and grouting mortar into casing pipe, pressing them through casing string-borehole annulus, placement of grouting mortar in casing string-borehole annulus and leaving it for waiting-on-cement-time. After pressing through spacer fluid in casing string-borehole annulus is "down-up" reciprocated one or more times, alternately pressing all or part of fluid out of the casing string-borehole annulus into the casing pipe and back at various heights and at various speed; simultaneously grouting mortar is reciprocated in a column or its headed portion is pressed through into the casing string-borehole annulus and is reciprocated together with spacer fluid; after reciprocating completion spacer fluid is pressed through into the casing string-borehole annulus.

EFFECT: upgraded quality of wells cementing.

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