PERCUSSIVE-DRAWDOWN BAILER Russian patent published in 2001 - IPC

FIELD: oil producing industry; applicable in cleaning of wells, sampling of well fluid and intensification of impact-wave action on hydrocarbon-containing formation due to drawdown effect. SUBSTANCE: percussive- drawdown bailer includes hollow cylinder with top and bottom guides. Located in guides for longitudinal fixed motion is striker. Bottom guide has limiting stop. Striker ahs drive, lock engageable with pressure retainers of work conditions. Striker lower end is flat whose cross-section area is larger than that of upper part. Striker lower end has piston valve. Upper guide is made in form of damping chamber, and bottom guide is in form of sleeve with side windows. Lock is made in form of cones whose vertexes are directed to opposite sides and connected with each other by eccentric. EFFECT: higher efficiency of impact-wave action, more reliable locking mechanism. 2 dwg