WELL EFFICIENCY RECOVERY AND START UP OF STAND BY WELLS WITH COMPLICATED DESIGN COLLECTORS IN ALFP CONDITIONS AND PRODUCTION STRING BOTTOM PART COLLAPSE Russian patent published in 2010 - IPC E21B43/32 E21B29/10 

FIELD: oil-and-gas industry.

SUBSTANCE: method of efficiency recovery and stand by wells, with collector of complicated design in abnormally low formation pressure conditions and production string bottom part collapse includes execution of repair-isolation works and reservoir opening. Sweep up the string, repair its compressed bottom, wash in a sand plug till depth of the nearest to a gas-water contact - GWC clay sub layer, descend in to the string a tail from casing pipes of a smaller diametre up to the sand plug head, with the tail head dislocation 20 m above of the reservoir roof, cement the tail with a cement slurry, leaving a cement barrel 1-2 m higher the tails shoe. After cement fixing - CFT drill the cement barrel, wash the sand plug up to the current GWC, through perforation holes with perforation interval 15-20 m³ of the water sealing composition, press it through 3-5 m³ of the cement slurry in to the reservoir, creating water sealing screen and stop over the defined height cement barrels sand plug. After the CFT execute perforation - hydro-sand-jetted or with powerful cumulative perforator - of the production string and the tail in interval over cement barrel head up to the reservoir roof and gas flow activation. The cement slurry contains portlandcement, superplastisiser C-3, polyvinyl alcohol, and polypropylene fiber.

EFFECT: well efficiency recovery and stand by wells operation start up reliability increase.

1 ex, 4 dwg