THERMAL RESISTANT POLYCATIONIC DRILL MUD Russian patent published in 2018 - IPC C09K8/24 

FIELD: drilling soil or rock.

SUBSTANCE: invention refers to drilling muds on the water basis and may find its application when drilling of oil and gas wells, mainly when drilling unstable clay rocks in terrigenous and salt deposits under high temperature conditions. Heat-resistant polycationic drilling mud contains, wt%: gel powder 3–5; copolymer of diallyldimethylammonium chloride and maleic anhydride in the ratio from 99:1 up to 92:8 – polyelectrolyte Silphoc 2540C 5–7; cationic polymer based on dadmach – Flodrill DB 45CR 1–2; water – the rest.

EFFECT: increased thermal stability of the solution up to 240 °C and more, ensuring stable values of filtration rates after exposure to high temperatures.

1 cl, 1 tbl