DRY LIGHT-WEIGHT PLUGGING MIXTURE Russian patent published in 2003 - IPC

FIELD: cementing and casing of oil and gas wells, particularly, dry plugging mixtures. SUBSTANCE: plugging mixture has Portland cement and complex light-weight additive including hollow microspheres and mineral additive. Complex light-weight additive contains mineral additive in form of IR-1 additive and additionally polymer or polymeric electrolyte, with the following amounts of components, wt.%: hollow microspheres 70-95; polymer or polymeric electrolyte 2-5; additive IR-1 3-25. Claimed dry light-weight plugging mixture contains the following amounts of components, wt.%: Portland cement 80-95; complex light-weight additive 5-20. EFFECT: prevented floating of microspheres, homogeneity and sedimentation stability of plugging mortar, rapid setting, higher isolating ability of plugging stone. 1 tbl, 3 ex