METHOD OF PREPARING NANOAPHRON DRILLING MUD Russian patent published in 2025 - IPC C09K8/24 B82B3/00 

FIELD: compositions for drilling of boreholes or wells.

SUBSTANCE: invention relates to methods of preparing drilling mud. Method of preparing water-based drilling mud containing nano-sized structures, involving mixing water and bentonite clay powder, adding a fluid-loss reducer selected from polysaccharides – sodium-carboxymethyl cellulose to obtain an aqueous mixture and mechanochemical activation. During primary synthesis, into said aqueous mixture located in a rotating mixing tank with a conical bottom of a hydraulic mixer with speed of 500 rpm or in mixing tank between two parallel-rotating in opposite directions working shafts with blades with speed of 400-800 rpm, reagents are further added in the following order: dry powders of polyacrylamide, an antifoaming agent, a cationic surfactant – a soluble salt, a bactericide, nanopowders Al₂O₃, SiO₂, Fe₂O₃ with a feed rate of 1-3 kg/min of each reagent and stirring for 30 minutes after the introduction of each reagent and for 1.5-2 hours after the introduction of all reagents. Subsequent circulation is carried out in said mixing tank for 2 hours with frequency of rotation of 800-1,200 rpm to obtain particle size of 20-40 mcm. During the secondary synthesis, the resulting mixture is hydraulically washed from the mixing tank, fed to the ultrasonic homogenizer suction pipe hole, passes through the impeller to impart acceleration, is fed into the working chamber, where particles of drilling mud reagents are subjected to ultrasonic dispersion by turbulent mixing with cavitation effect, shock-wave and oscillatory movements, by supplying a high-frequency sound wave with a constant amplitude, crushing the rotor and the stator at a high pressure of 40 MPa by rotating movable calibration knives, with a rotation frequency of 3,000-12,000 rpm, jet feed rate of 140-180 m/s, grinding with adjustable gradation to coarse – medium – fine – superfine grinding in order to obtain nano-sized structures in drilling fluid with dimensions from 10 to 100 nm, with a smooth polished smoothed surface, stable distribution on the entire volume, a homogeneous, ultrafine, chemically pure composition with the following ratio of components, wt.%: bentonite clay powder is not more than 3; sodium-carboxymethyl cellulose biopolymer 1.5-9.0; polyacrylamide 0.2-2; antifoaming agent 0.2-0.4; cationic surfactant 0.2-2; bactericide is not more than 0.2; nanopowders Al₂O₃, SiO₂ and Fe₂O₃ 0.5-5; water – balance.

EFFECT: preparing a drilling mud which can effectively plug pores in low-permeability collectors, interpore channels and fractures, form a structure with variable rheological properties and increase stability of well walls in unstable terrigenous rocks.

1 cl, 1 dwg, 1 tbl