WELL CLEANING STRAINER Russian patent published in 2012 - IPC E21B43/08 

FIELD: oil-and-gas production.

SUBSTANCE: proposed strainer comprises outer tube with connectors on ends and lateral holes, inner tube with holes, filtration element secured between said tubes and their holes and locked at appropriate top and bottom thrusts, and wave converter. Inner tube is arranged coaxially inside outer tube and locked at its top part. Inner tube top end is rigidly jointed with outer tube by top thrust while bottom end is free. Filtration element is made up of wire coiled over height with turn-to-turn inserts to allow uniform slots along the entire length and filtration element perimetre. Bottom thrust is made up of a piston fitted into outer tube under lateral holes for lengthwise displacement. Wave converter is made up of compression spring loading bottom thrust upward from the limiter arranged below bottom thrust, inside inner tube, to allow lengthwise displacement and locking.

EFFECT: expanded operating performances due to possibility to use said strainer with whatever deep-well pumps.

1 dwg, 2 cl