DEVICE FOR MEASUREMENT OF PIPE STRING LENGTH Russian patent published in 2000 - IPC

FIELD: means for control over well repair process. SUBSTANCE: device in additional to other components has pipe string displacement transducer. The latter includes immovable body with pressure roller and turning body with measuring roller. Secured between pressure roller and turning body is spring intended for developing of force exerted on rope on which pipe string is suspended. To develop additional force on rope, measuring roller is made hollow to accommodate permanent magnets. Rigidly secured at same axis with measuring roller is perforated disk which may be engageable with two variable-induction pickups intended for scanning of disk turning angle. Signals from outputs of variable-induction pickups arrive at inputs of unit for determination of direction of movement and interpolator of signals. Outputs of unit for movement direction determination and signal interpolator are connected to inputs of arithmetic logical unit. Connected also to other of arithmetic logical unit are wedge grip position pickup and comparison unit giving permission signal for counting by arithmetic logical unit of count pulses coming from signal interpolator. Connected to comparison unit inputs are hook load transducer and interlocking initial level setter. Signal from arithmetic logical unit arrives at indicator. EFFECT: simplified design of device and higher accuracy of measurement of pipe string length. 6 dwg