METHOD FOR PREVENTING OCCURRENCE OF INTER-CASING AND INTER-LAYER FLOWS IN WELL Russian patent published in 2023 - IPC E21B33/14 C09K8/42 

FIELD: well operation.

SUBSTANCE: invention relates to a method for preventing the occurrence of inter-casing and inter-layer flows in a well. The method involves fastening casing strings by cementing with lifting and pumping cement mortar above the roof of the productive isolated formation. The method also includes installing a calculated volume of an insulating composition with viscous elastic properties under the cement mortar. A volume of insulating composition is pumped in the form of a pack at the final stage of cementation between the cement slurry and the second separation buffer. The volume of the insulating composition is determined based on the specified height of placement in the annulus, which is determined by the required minimum value of permissible stresses at the “composition-pipe” and “composition-rock” contacts, taking into account the diameter of the barrel and the cemented casing, formation pressure and temperature, cavernosity and filtration and reservoir parameters of the formation in the near-wellbore zone of the cemented interval and parameters of the formation fluid. A set of laboratory studies is also carried out, and on the basis of these data a formulation of an insulating composition is selected; for the temperature range 20-70°C, epoxy resin is used in a concentration of 68-70%. For temperature range 70-165°C epoxy resin in a concentration of 57-58%, an anhydrous hardener in a concentration of 41-42% and a setting accelerator in a concentration of up to 1% are used.

EFFECT: simplifying and reducing the time of carrying out a method for preventing the occurrence of inter-casing and inter-layer flows in a well.

1 cl, 1 tbl