METHOD OF KILLING OF OIL WELLS WITH HIGH GAS FACTOR IN PERMAFROST CONDITIONS Russian patent published in 2017 - IPC E21B43/12 C09K8/48 C09K8/493 

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to oil and gas industry, namely, to killing of oil wells. The oil well killing method includes damping injection into the well through the tubing string of potassium chloride-based solution with the density required for formation conditions. Then the viscoelastic composition is injected which comprise the saline solution based on potassium chloride, 0.1 wt % of caustic soda and thickener polymer with filler -. 0.75 wt % of xanthan gum and 2.5 wt % of vermiculite. The injected components are flushed through the perforations in the production casing and through the fracture formed during the fracturing in the near-well zone with formation in the bottom and near the wellbore of the blocking screen layer which is impermeable for water and gas contained in crude oil. Then only saline is injected into the annulus through the tubing string by creating the direct circulation between the production string and the tubing lowered into it.

EFFECT: invention consists in improvement of the reliability of oil well killing and blocking of bottomhole formation zone in permafrost conditions without thawing.

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