DRILLING FLUID ON SYNTHETIC BASIS Russian patent published in 2012 - IPC C09K8/08 

FIELD: oil and gas industry.

SUBSTANCE: drilling fluid on synthetic basis includes the following, wt %: water 20.3-47.3, polyatomic alcohol 20.3-47.3, biopolymer 0.23-0.34, sodium formate or sodium acetate 20.3-27.0, anionic emulsion ROSFLOK PV 3.4-6.8, bactericide 0.07-0.14, disperse chalk 1.7-5. Drilling fluid is prepared by introduction of biopolymer to water at constant mixing; polyatomic alcohol is added to the formed structured liquid in portions after dilution; after that, anionic emulsion is added; in order to control polarity of drilling fluid components and increase its heat resistance, there added is salt-electrolyte; in order to prevent biological decomposition of biopolymer, the latter is treated with bactericide; weighting-up of the fluid is performed with disperse chalk; drilling fluid is obtained at mixing with blade agitator with speed of 5000 rpm.

EFFECT: maintaining rheologic and filtration parameters of the fluid.

3 cl, 5 tbl