COILED TUBING INJECTOR WITH HYDRAULIC TRACTION SLIP MITIGATION CIRCUIT

摘要

When one of at least two independently driven gripper chains (102) of a coiled tubing injector (100) begins to turn faster than another one of the injector's other independently drive gripper chains by an amount that indicates slipping of one of the independently driven gripper chains relative to tubing (109) being held between the driven gripper chains, a hydraulic timing circuit (318), which is coupled with the driven chains through hydraulic timing motors (214, 216), generates a pressure signal that causes the injector's hydraulic traction system to increase the hydraulic pressure applied by hydraulic cylinders (220) to generate a normal force applied by grippers on the chains to the tubing.