GYPSUM-LIME DRILLING MUD ON SODIUM FORMATE Russian patent published in 2024 - IPC C09K8/08 

FIELD: oil and gas industry.

SUBSTANCE: gypsum-lime drilling mud contains, wt.%: sodium formate 8.287; bactericide 0.083; starch reagent 2.072; polyanionic cellulose “ПАЦ” "ХимПАК" 0.166; xanthan biopolymer 0.166; inhibiting composition Ingidol “ДТ” 0.041; carbonate weighting agent – marble chips 17.404; lubricating additive 0.829; gypsum 0.829; drilling agent "ФХЛС" 0.414; slaked lime 0.095; water 69.614.

EFFECT: maintaining the integrity of the productive formation in the intervals of weakly cemented rocks and in unstable clay deposits, including those represented by non-swelling highly lithified mudstones and clay shales, achieving the design bottomhole by drilling without complications, maintaining the quality of the extracted core, reducing the risks of environmental pollution.

1 cl, 1 dwg, 2 tbl