Oil pumping polish rod fatigue performance experiment platform under stretching and bending superposition deformation working condition

Abstract

The invention discloses an oil pumping polish rod fatigue performance experiment platform under a stretching and bending superposition deformation working condition, wherein the oil pumping polish rod fatigue performance experiment platform comprises a main body frame, a loading system, a measuring system and a control system; the loading system further comprises a lateral extrusion device, and a plurality of groups of camera units are further arranged on the main body frame right opposite to the lateral extrusion device; and an extrusion arc plate is arranged at the end of the lateral extrusion device, the outer surface of the extrusion arc plate is attached to the outer circle face of the oil pumping polish rod sample, and the contact position of the extrusion arc plate and the outer surface of the oil pumping polish rod sample can be automatically adjusted. According to the oil pumping polish rod fatigue performance experiment platform under the stretching and bending superposition deformation working condition, the fatigue performance of the oil pumping polish rod under the actual stretching and bending superposition deformation can be well simulated under the condition that the experiment condition and the experiment process are strictly controllable and adjustable; and a reliable experiment platform is provided for selection and service life prediction of the oil pumping polish rod and well site management.

Description

technical field [0001] The invention relates to fatigue performance experimental equipment for polished oil rods, in particular to an experimental platform for fatigue performance of polished oil rods under the working conditions of stretching and bending superimposed deformation. Background technique [0002] As the current main oil production method at home and abroad, the oil sucking rod, a key component of artificial lift oil production, is facing an increasingly complex service environment. For oil pumping rods, due to the existence of deep wells, ultra-deep wells and deviated wells, and unsatisfactory wellhead alignment, the oil pumping rods need to bear axial tension-tension alternating loads and bending alternating loads at the same time during service. The failure stress is dominated by tensile stress, especially the convex and curved side of the polished rod surface bears more severe superimposed tensile stress, which is the preferential position for fatigue failur...

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Problems solved by technology

[0003] However, in terms of equipment for testing and evaluating the fatigue performance of oil pumping rods, there are still serious problems: the laboratory environment is mainly based on standard fatigue testing machines, and standard fatigue testing machines are usually composed of a main frame, a loading system, a measuring system and The composition of the control system. The loading system can be used to load the material sample under different cyclic load conditions. The measurement system can be used to obtain the variables such as the load and displacement of the material sample in real time, and the control system can realize the entire fatigue testing machine. Precise operation under the set conditions, and then obtain the fatigue performance indicators such as fatigue life and fatigue limit of the oil pumping rod under different conditions, but there are still relatively simple situations in the fatigue performance detection of the oil pumping rod, such as single evaluation pumping The axial tension-tension fatigue performance of the oil polished rod, or the single evaluation of its rotational bending fatigue performance, or a certain theoretical analysis and calculation of the results obtained by the two respectively; in the field experiment, it is mainly carried out on the failed oil pumped polished rod sample. Post-analysis statistics and induction to evaluate the fatigue performance of oil pumping rods, and a small amount of field experiments can be carried out in a few cases

However, there is a large gap between the data obtained by the existing standard fatigue testing machine and the fatigue under the superimposed deformation of the oil pumping rod under tensile-bending deformation. Very limited on-site experiments or statistical analysis of actual failure samples, whether it is the number or the control of working conditions , it is difficult to meet the actual needs

It can be seen that the fatigue performance test of the above oil pumping rod under the condition of tension and bending superimposed deformation is quite different from the actual working condition of the oil pumping rod

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