SYSTEM TO MEASURE MECHANICAL DRILLING LOADS COMPRISING RESONANCE-TYPE TRANSDUCER Russian patent published in 2007 - IPC E21B44/00 

FIELD: drilling equipment, particularly system to measure mechanical loads in well drilling.

SUBSTANCE: system comprises measuring part including body defined by drill string section provided with at least two extensions spaced apart by predetermined distance in longitudinal drill string direction and connected to inner surface thereof. The extensions are adapted to secure resonance cord ends. System has inner pipe having length exceeding distance between the extensions and hermetically secured inside body by the first end thereof. Formed on opposite, the second, pipe end is annular extension air-tightly connected to inner body surface. At least one resonance cord is connected to body extensions by ends thereof. System includes at least one electronic excitation and resonance cord resonance changing unit connected to inner pipe surface facing the body, as well as remote computing unit to calculate axial force acting on drilling string during drilling operation from resonance cord resonance information received from said electronic unit. Other system embodiments are also disclosed.

EFFECT: increased reliability and efficiency, decreased costs for drill string stress measurement.

36 cl, 2 dwg