DRILLING MUD WITH PLUG-IN SOLID PHASE PETRO PLUG Russian patent published in 2020 - IPC C09K8/08 

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: invention relates to oil and gas industry, in particular, to self-regulating inhibiting calcium drilling mud used in drilling wells under difficult conditions. Drilling fluid contains the following, wt. %: biocide Petro Cide 0.03-0.05; oleophilic lactin S-Drill Block 0.35–2.0; xanthan biopolymer Xanthan Petro L 0.28–0.35; potassium chloride 3.0–13.0; plugging 3.0–10.0; Petro Lube lubricant - 1.39–3.0; antifoaming agent Petro Def 0.05–0.08; different-fraction microcalcite 6.0–2.3; citric acid 0.14–0.24; polycarboxylate lignin S-Drill Cl 0.0–0.8; caustic soda 0.0–0.02; modified starch Petro Starch U 0.0–2.5; starch reagent S-Drill St 0.0–2.0; sodium chloride 0.0–14.0. Drilling fluid can additionally contain cement plugging in amount of 17.0–20.0 wt. %.

EFFECT: technical result is prevention of talus and rock slopes, reduced probability of initiation of flushing fluid absorption due to minimizing effect of pulsating pressures on walls of well, high inhibitory capacity with respect to clay shale, possibility of performing operations to eliminate absorption of flushing fluid without involving third-party organizations for installing cement bridges and, as a result, considerable time saving.

1 cl, 2 dwg, 4 tbl, 2 ex