PLUGGING MATERIAL FOR MAKING OF BRIDGES IN WELL DRILLED INVERTED-EMULSION DRILLING MUD (VERSIONS) Russian patent published in 2014 - IPC C09K8/467 

FIELD: oil-and-gas industry.

SUBSTANCE: plugging material, in compliance with first version, comprises components at their following ratio, in wt %: plugging Portland cement - 95.0-97.0, expanding additive - calcium hydrosulphoaluminate - 3.0-5.0, said filtration reducer - 0.1-0.5, said nonionic surfactant - 0.1-3.0, said plasticiser - 0.01-0.5, said foam killer - 0.2-0.4, calcium chloride - 0.01-6.0, water for water-cement ratio of 0.4-0.52.In compliance with second version, plugging material contains additionally the following components, in wt %: surfactant 4 or surfactant 6 - 0.05-1. Note here that nonionic surfactant-to-surfactant 4 or surfactant 6 makes 65:35, respectively.

EFFECT: guaranteed reliability, optimum hardening terms at low water-cement ratio.

3 cl, 2 tbl, 2 dwg