CATIONIC DRILLING MUD Russian patent published in 2018 - IPC C09K8/12 

FIELD: drilling of soil or rock.

SUBSTANCE: invention relates to water-free mud and can be used for drilling oil and gas wells, mainly when drilling productive seams and unstable clay rocks under the influence of high temperatures up to 160 °C. Cationic drilling mud contains, by mass%: copolymer Silfok 2540C, obtained by copolymerization from a mixture of monomers – diallyldimethylammonium chloride and maleic anhydride in the ratio from 99:1 to 92:8, 5–7; aluminum sulphate 10–15; caustic soda 3.6–5.4; cationic polymer based on dadmach – Flodrill DB 45CR 0.5–1; water – the rest.

EFFECT: increase in the thermal stability of the solution when drilling productive seams and unstable clay rocks under conditions of exposure to temperatures up to 160 °C.

1 cl, 1 tbl