METHOD OF PRODUCTION STRING SEALING Russian patent published in 2018 - IPC E21B33/138 C09K8/42 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to oil and gas industry, in particular, to methods of sealing the production well string. Method includes determining the interval of disruption of the production string, descent of the tubing in the disturbance interval or lower. At the same time, before slipping the tubing below the interval of violation, a current slaughter is established for 4–10 m. After descent, the tubing is washed with a solvent of asphalt-resin-paraffin deposits, followed by washing the production column from the solvent and filling with a liquid that does not mix with the sealing compound and density less than this composition. Then the substance of the composition is injected into the disturbance interval in a volume of 100 liters per 1 meter of the disturbance interval, followed by a sufficient time for wetting the surface of the disruption of the production column. Injection of the sealing composition along the tubing into the interruption interval is carried out between the separation plugs. After displacement by the sealing compound of the well fluid from the disturbance interval, the tubing is raised above the upper boundary of the sealing compound. Before selling the sealing compound in the disturbance interval, an exposure is made sufficient to immerse the sealing composition on the bottom of the well, and wash out the surpluses of this composition. In this case, 83.5–91.0 % by weight of the epoxy-dian resin, 9.0–16.5 % by weight of the hardener are used as the sealing compound, and monoethanolamine is used as a co-ordinator of the composition.

EFFECT: increase in the efficiency of repair and insulation work during the sealing of the production well string.

1 cl, 4 ex, 1 tbl