DEVICE FOR PIPE CLEANING IN WELL Russian patent published in 2006 - IPC E21B37/00 E21B28/00 

FIELD: well equipment, particularly for pipe or pipe string cleaning of scales by repeatedly striking pipe walls with working body with high frequency and regulated amplitude, to eliminate pipe sticking in well by exciting transversal oscillations by striker.

SUBSTANCE: device comprises pipe string and striker adapted to hit pipe walls. The device is connected to additional pipe string provided with support on lower end and is submerged in pipe string to be cleaned. Pendulum-like striker is suspended in additional pipe string so that the striker is spaced predetermined distance from additional pipe string bottom to provide free radial striker movement. Ball-like flow shutoff means is arranged over pendulum-like striker and has diameter less than inner diameter of additional pipe string. Ratio between ball-like flow shutoff means diameter and inner additional pipe string diameter is defined as d/D_in≤0.85, where D_in is inner additional pipe string diameter, d is ball-like flow shutoff means diameter.

EFFECT: increased efficiency of pipe interior cleaning of scale.

1 dwg