CLAYLESS DRILLING MUD Russian patent published in 2012 - IPC C09K8/12 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to clayless drilling muds used for drilling processes, mainly during drilling of productive formations in wintertime at the temperature of 20°C below zero. Clayless drilling mud containing fluorine-containing copolymer of acrylamide and acrylic acid and water contains copolymer of the following general formula: of molecular weight 1.2·10⁶ with fluorine content of 2-4%, at the following ingredient ratio, wt %: the above copolymer 0.1-0.15, and water is the rest.

EFFECT: stable operating parameters of the mud up to 100 days at the effect of decreased temperatures.

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