OIL-WELL COMPOSITION FOR STEAM-INJECTION WELLS Russian patent published in 2009 - IPC C09K8/467 

FIELD: oil and gas production.

SUBSTANCE: invention relates to drilling and operation of oil and gas wells, in which there are applied thermal methods of increasing of reservoir recovery. Oil-well composition for steam-injection wells contains wt h.: Portland cement 50-80, high-silica sand 10-45, amorphous silicon dioxide up to 10, water up to "в/ц" 0.35-0.52. Oil-well composition in the capacity of regulator of processing characteristics additionally contains accelerant of setting-time - calcium chloride or sodium chloride up to 5 wt h. and/or oxy-ethyl-cellulose up to 0.5 wt h., and/or plasticiser - lignosulfonates or Melflux, or Cemplast MF of grade b.

EFFECT: absence of dehydration in grouting mortar, reduction of filtration, increasing of pumpability and setting time of cement stone in conditions of normal temperatures, increasing of adhesive behaviors of formed grouting stone and in providing of stability of it at conditions of sharp temperature fall from 22°C up to 180°C at simultaneous keeping of high durability at cyclic thermal influence during long period.

5 cl, 2 tbl, 1 ex