COMPOSITION OF POLYSACCHARID LIQUID FOR WELL KILLING AND FLUSHING AND METHOD FOR ITS PREPARATION AND APPLICATION Russian patent published in 2018 - IPC C09K8/40 C09K8/42 C09K8/524 E21B37/00 E21B37/06 

FIELD: oil production industry.

SUBSTANCE: invention refers to the oil and gas production industry, in particular to the formulations for killing and flushing wells. Composition of a polysaccharide liquid for flushing wells or field pipelines or for killing wells, obtained by dissolving the biocide "Biolan" in fresh or mineralized water, represented mainly by the solution of monovalent cations, dissolution and hydration in the resulting solution of guar gum, followed by the introduction of the complex Neftenol USP reagent with stirring until the micellar dispersion is obtained, followed by the addition of boron cross-linking agent SP-RD and stirring until complete crosslinking, with the following ratio of components, WT%: guar thickener 0.2-1.0, the specified cross-linking agent 0.2-1.0, reagent USP Neftenol 6.0-10.0, biocide "Biolan" 0.004-0.01, the specified water is the rest. Method for flushing wells and cleaning the perforation interval from asphalt-resin-paraffin deposits in wells with abnormally low reservoir pressure, including injection of the above composition into the annulus of the well as the blocking package, an endurance for placing it at the bottom of the well, subsequent backwashing of the well by means of pumping into the well annulus of the drilling mud, in which the aqueous solution of the Neftenol USP reagent is used, heated to 30-40°C, with the concentration of 60-100 liters per 1 m³ of fresh or mineral water, the volume of the blocking package is determined by means of calculation taking into account the volume of the sump and leaving the riser overlapping the perforation interval by 100-200 m, and its density exceeds by 20-50 kg/m³ the density of the mentioned washing liquid. Method for flushing wells, including injecting into the well the above mentioned composition and circulating it complete package of the well. Method for flushing commercial pipelines, which involves pumping the washing liquid heated to 30-40 °C into the field pipeline, as the aqueous solution of Neftenol USP reagent with the concentration of 60-100 l per 1 m³ of fresh or mineral water, and then squeezing the above mentioned solution. Method for flushing commercial pipelines, which involves pumping the above mentioned solution into the field pipeline.

EFFECT: technical result is the increase in processing efficiency.

5 cl, 2 tbl