RECOVERY METHOD OF WATER-PRODUCING OIL-AND-GAS WELL IN CONDITIONS OF ABNORMALLY LOW FORMATION PRESSURES Russian patent published in 2011 - IPC E21B43/00 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to recovery of water-producing oil-and-gas well in conditions of abnormally low formation pressures. According to the method, the well is killed, sand plug is flushed in the well shaft below current gas-water contact at the level of 2-5 m. Then, production string is perforated below current gas-water contact at the level of 2-3 m and above current gas-water contact at the level of 1-2 m. Through perforated holes made for water insulation there pumped is water-insulation composition, then it is pumped to the depth of formation along radius and water insulation interval is fixed with cement solution. After cement is thickened, cement plug is drilled in the well shaft to the depth of upper holes of perforation interval for water insulation. Then, shank - section of pipes of smaller diameter is lowered to the well shaft, cemented so that cement column is left in inner cavity with height of 0.2-0.5 m. Tubing string is lowered to the well to the depth of 2-5 m above head of shank, perforation assembly is lowered through them and shank and production string is perforated above water insulation interval at the level of 1.5-3.0 m to the roof of productive formation. Influx is induced from formation; after that the well is put into operation.

EFFECT: providing insulation of formation water influx, tightness of production string and additional gas production from earlier water-producing and non-operating well.

6 dwg