WELL DRILLING RIG Russian patent published in 2007 - IPC E21B25/02 

FIELD: drilling, particularly well drilling along with core taking with the use of removable sampling barrels.

SUBSTANCE: drilling rig comprises drill string with rock-cutting tool, removable sampling barrel having body with stop mechanism, stop mechanism drive and overshot. Above components are located in the body. The stop mechanism retains sampling barrel in working position. Stop mechanism drive has conical mushroom member and head to cooperate with stop mechanism. The overshot comprises blocking bush and spring-loaded double-armed levers carried by common axle. Upper arm of each lever is provided with boring for blocking bush receiving. Lower arm has leg and thrust arranged between axle and leg. The thrust is adapted to cooperate with conical mushroom member. Upper body part has cone to cooperate with overshot legs in working position.

EFFECT: possibility to obtain reliable information concerning stop mechanism actuation and, hence, provision of sample obtaining from wells drilled without flushing fluid usage.

2 dwg