BASE PLUGGING MATERIAL FOR CEMENTING WELLS IN RESERVOIR INTERVAL Russian patent published in 2023 - IPC C09K8/467 E21B33/138 

FIELD: oil and gas.

SUBSTANCE: base plugging material for cementing wells in the interval of the productive formation includes a mixing fluid - water, and a base consisting of Portland cement PTC IG-CC-1, a filtration reducer, a mineral additive, a defoamer and an expanding additive, while the filtration reducer is a polyacrylamide-based synthetic polymer, the defoamer is a silicone emulsion based on modified linear and branched polydimethylsiloxanes, the expanding additive is a product based on calcium oxide with an active substance content of at least 95%, the mineral additive is Ultracement-5 micronized cement with a content of particles up to 5 mcm in size of at least 90%, and additionally contains a gas-blocking additive based on a copolymer of vinyl acetate and vinyl ester of versatic acid, having polyvinyl alcohol as a protective colloid and an adhesive additive - a reagent based on vinyl acetate polymerization products in an aqueous medium in the presence of initiator and protective colloid of polyvinyl alcohol - coarsely dispersed homopolymer polyvinyl acetate dispersion in the following ratio of components, wt.%: Portland cement PCT IG-CC-1 72.2-92.1, filtration reducer 0.55-0.6, defoamer 0.2- 0.4, mineral additive 4.5-11.0, expansion additive 1.75-7.2, gas-blocking additive 0.9-1.4, adhesive additive 0-7.2, and the water content in the solution ensures the water-cement ratio 0.45-0.55.

EFFECT: new material.

1 cl 2 tbl