CLAY-FREE INHIBITING DRILLING MUD Russian patent published in 2016 - IPC C09K8/10 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry, in particular, to water-based drilling mud used in drilling wells for oil and gas in potentially unstable clay rocks. Clayl-free inhibiting mud contains filtering reducer - high-viscosity carboxymethyl cellulose, inhibitory and weighting additive - potassium carbonate, inhibiting additive - Glycoyl, builders - xanthan biopolymer, lubricant additive, water and adhesively bridging additive, which is used as a carbon product - granulated carbon black, fine spherical graphite, with following ratio of ingredients, wt%: high-viscosity carboxymethyl cellulose - 0.4-1.0, potash - 5.0-20.0, Glycoyl - 1.0-2.0, xanthan biopolymer - 0.3 0.4, carbon product - 0.5-1.5, lubricant additive - 0.5-1.0, water - balance.

EFFECT: result is obtaining a highly inhibiting composition for maintaining stability of lithified clay rocks having mud, inhibiting and lubricating capacity.

2 cl, 2 tbl