INJECTOR OF COILED TUBING WITH TENSION RELIEF Russian patent published in 2017 - IPC E21B19/22 

FIELD: engine devices and pumps.

SUBSTANCE: injector of coiled tubing includes several clamping circuits, each of which consists of a closed circuit with several gripping elements installed thereon. Each of the several clamping circuits includes sections arranged with respect to each other so that they form a gripping zone for gripping said pipe when it is placed between said sections of clamping circuits. The gripping zone has a central axis coinciding with the central axis of said pipe passing through the gripping zone. The injector also comprises at least one means to relief tension in at least one of the clamping circuits as it passes through the gripping zone and a shoe for each of the several clamping circuits extending beyond said portion of the clamping circuit and providing pressing of gripping elements of the circuit to said pipe as it passes through the gripping zone with force directed perpendicularly to the surface of said pipe. The shoe has, at least, one of several clamping circuits formed thereon with at least one tension relief region for dividing the gripping zone into a tension relief segment located between two traction segments. The tension relief area of the shoe provides reduced amount of force applied by the gripping element as it passes through the tension relief segment, in comparison with the magnitude of the force applied by the gripping element during its movement in any of the two said traction segments.

EFFECT: providing unloading of elastic deformation occurring in coiled tubing as it passes through the gripping zone.

13 cl, 5 dwg