Design of Measure and Control System of the Ring Block Casing Wear Tester

In deep wells and ultra-deep wells the complex geological conditions often result in serious casing wear. In order to obtain the wear efficiency which is used to compute the wear depth of downhole casing, the ring block drillpipe casing wear tester is developed. The measure and control system which include the measure circuits of contact forces between casing and drillpipe samples, the measure circuits of the friction forces are main component of wear tester. It is very important to design the measure and control system of tester. The paper also develops the calibration method of the loads sensors used to measure the contact and friction force. The wear tester can accurately measure the wear efficiency and the friction coefficient needed by casing wear prediction.