| Sucker rod as the one of key components in the oil and gas field exploitation, its quality decides the efficiency of production. The sucker rod failure most because the alternate loads make it broken. Analysis of the sucker rod and proposing the method of forecasting its residual life could improve sucker rod's using rate effectively.From endurance testing of pump rod, fined change rules of leading edge of cracking, obtained relationship between depth and area of crack and relationship of crack area and remaining life, use Paris formula, established relation of ultrasonic inspection and crack depth, and relation of crack detection signal and crack spread law, proposed predict method of remaining lifetime of pump rod by ultrasonic inspection. Comparing the results with the residual life tested by simulation test, the accuracy rate of test is over72%.The main contents of this article are that:1. This paper starts of the history of oil production wells ,and does the investigation and research, statistics rod production wells Fault, the failure of sucker rod types and failure factors, identify the main rod cracks factors - fatigue fracture;2. Crack against fatigue fracture, the paper on D-20CrMo steel rod material three-point bending experiments to find out what the parameters of fracture toughness, fatigue crack growth rate defect to the probability distribution of. Through the probability distribution of research shows that D-20CrMo steel rod fracture toughness of the material and mechanical properties are subject to normal, and that D-20CrMo steel rod crack propagation rate constant of the material in C, m;3. Adopt immersion ultrasonic apparatus monitoring the fatigue fracture test methods forecast Grade D 20CrMo steel rod of residual life, the establishment of ultrasonic signals and crack depth of the relationship between the sucker rod, thereby establishing ultrasonic flaw detection signal through discriminant rod residual life of the simplified method.
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