HYDROACOUSTIC BAFFLE Russian patent published in 1995 - IPC

FIELD: drilling of deep wells. SUBSTANCE: hydroacoustic baffle has body with outer and inner coaxial walls rigidly connected in upper part with sub of drill string. Located between body walls is circular floating piston forming, together with body, chamber filled with gas and hollow hydraulically communicated with inner hydraulic channel of body. Body outer wall is rigidly connected with lower sub. Vibrations arising in drilling propagate from drilling bit through drill string above hydroacoustic baffle without reflecting to hydraulic channel. Installed on body inner wall under floating piston is limiting ring with channels to pass drilling mud. Hydroacoustic pulses propagate in hydraulic channel inside drill string from bottom hole up to floating piston and are reflected by boundary with compressed gas back to hydraulic channel. Area of cross-section of floating circular piston is larger than area of cross-section of hydraulic channel of body inner wall that provides for reflection of 75% of hydroacoustic pulses which reach the hydroacoustic baffle. EFFECT: higher efficiency. 2 cl, 1 dwg