METHOD FOR CEMENTATION OF CASING STRING IN THE WELL Russian patent published in 2004 - IPC

FIELD: oil and gas extractive industry.

SUBSTANCE: method includes preparation of well, lowering of casing column into it having locking device in lower section, made with possible closing from effect of vertical axial force upward along column of backfill material in behind-column space, sealing of behind-column space, pumping of backfilling material into behind-pipe space, raising of washing pipes for small height and removing backfilling material from there be means of forward or backward washing. Washing pipes after their mounting to locking device and partial unloading are immediately raised a bit. Inter-pipe space is sealed and backfilling solution is pumped through these into behind-column space. After appearance of backfilling material on well mouth its circular circulation is performed until receiving solution stability in matter of thickness. Then through washing pipes backfilling material is pushed by calculated volume of pushing liquid with certain volume left in these. Pumping pressure is dropped and after that remaining backfilling material is removed from these.

EFFECT: higher cementation quality, simpler technology and higher ecological safety.

1 dwg