BOTTOMHOLE SHOCK ABSORBER Russian patent published in 1997 - IPC

FIELD: devices for damping vibrations in drilling, mainly, horizontal sections of development and exploratory wells. SUBSTANCE: device has body, stem and flexible member located between them in form of filler of small length with pistons at its ends for interaction with stem, and filler of large length with pistons installed in its ends and having flanges. Installed on outer surface of filler of large length is flexible shell. Stem in place of interaction with filler of small length has thin-walled section and collars for interaction with pistons of small-length filler. High-load action of shock absorber causes relative motion of body and stem resulting in interaction of piston flanges of large-length filler with flanges of small-length filler pistons. This brings about change in characteristic of flexible member to raise the bearing capacity. EFFECT: higher efficiency. 2 cl, 1 dwg