BACK FILLING COMPOSITION Russian patent published in 2009 - IPC C09K8/46 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to oil extraction, particularly to back filling compositions designed for isolation of zones of loss and for repair-isolation works in well. The composition contains a clay powder, sodium metha-xylitol, poly-acryl-amide, water and plasticizer - a product on base of saponated stillage bottoms from production of synthetic fat acids containing not less, than 30% of solid residue, not less, than 1.7 mg-equiv/l of sodium soaps of synthetic fat acids and not more, than 0.1% of free alkali per solid residue or a product on base on saponated with potassium hydroxide or mixture of potassium hydroxide and sodium hydroxide stillage bottoms form production of fat acids of vegetable or animal oil with titre from 5 to 65 and with contents of residual alkali not less, than 0.05% per solid residue at the following ratio of ingredients, wt parts: clay powder 60-90; sodium metha-xylitol 5-30; poly-acryl-amide 0.01-0.5; the above said plasticiser 1-10, water 80-150.

EFFECT: upgraded isolating efficiency due to increased value of plastic hardness of forming back-filling stone and due to maintaining this value during considerable period of time with simultaneous maintaining good mobility and pumping ability at initial period of time.

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