HEAVY PROCESS FLUID, COMPOSITION AND METHOD FOR ITS PREPARATION, METHOD OF WELL KILLING WITH HEAVY PROCESS FLUID Russian patent published in 2024 - IPC C09K8/42 E21B33/138 

FIELD: oil industry.

SUBSTANCE: invention relates to completion and repair of oil and gas wells, and can be used in conditions of abnormally high formation pressures and in conditions of low temperatures of the Far North. Heavy process fluid for well killing is an aqueous solution with density of 1.32 g/cm³ to 1.62 g/cm³ at 20 °C and includes the following, wt.%: calcium-ammonium nitrate 40.0–45.0; calcium chloride 13.3–15.8; zinc chloride 17.0–18.5; corrosion inhibitor 2.5–4.0; water—balance. Also disclosed is a method for preparing said process fluid, a method for killing using said process fluid, composition for preparation of heavy process fluid for well killing.

EFFECT: providing simultaneously low values of corrosion rate, freezing point below minus 35 °C of heavy process liquid, cryostability, expansion of range of change of density of said liquid, possibility of using said fluid in a wide range of formation pressures, safety and simplicity of preparation, preservation of filtration characteristics of wells during repeated commissioning.

20 cl, 4 tbl, 3 ex