INHIBITING DRILLING FLUID FOR DRILLING IN UNSTEADY TERRIGENOUS DEPOSITS Russian patent published in 2021 - IPC C09K8/24 

FIELD: drilling.

SUBSTANCE: invention relates to construction of petroleum and gas boreholes, primarily horizontal boreholes in the intervals of unstable terrigenous deposits. The inhibiting water-based drilling fluid used primarily for construction of horizontal boreholes in the intervals of unstable terrigenous deposits includes, % wt.: polymer silicate reagent POLYSIL Potassium containing high-modulus sodium and potassium silicates, high molecular weight acrylic polymer and modified bitumen, 1.0 to 2.0; complex reagent-stabiliser of drilling fluids, pitch carbolignosulphonate PCLS including tall oil pitch saponified with caustic soda, lignosulphonate and carboxymethyl cellulose, 1.0 to 4.0; xanthan biopolymer 0.1 to 0.2; potassium chloride 3.0 to 8.0; microcalcite 5.0 to 10.0; water the rest.

EFFECT: increase in the inhibiting and a decrease in the dispersing properties of the drilling fluid, provision of low filtration indicators and stability of parameters in downhole conditions, a decrease in the friction coefficient.

3 cl, 2 tbl