Research On Load-bearing Capacity And Safety Evaluation Of JJ113/32 Workover Rig Derrick

Workover rigs are necessary equipment of under the effect and replacing tools in various oilfield operating. However derrick is the key part of workover rig. During workover rig completing its task, the derrick will bearing large added dynamic loads on the time of start drilling and stopping especially, and producing severe vibration. Additionally, by the reason of cyclical incentive of wheel, derrick will produce different forms of vibration and different levels. The bad design not only waste raw and processed materials but also event accidents. So it is necessary to research the static characters and dynamic characters of derrick, search the weak parts and security risks, and provide theory criterion for workover rig works, avoid the event of accidents, further enrich,perfect and develop the analysis theory of workover rig derrick structure.This paper according to the actual structural features, establish the finite element model, by using ANSYS finite element analysis software carry static analysis through it under the condition of maximum load, get the stress and displacement in the appointed time. Modal analysis as one of the method of structural dynamic characteristics researching, gradually become the core of dynamic analysis and design regions. It determines natural frequency and mode shape are important parameters in the design of structural bearing dynamic loads, so it is the start of transient analysis and others. This paper complete the modal analysis of drilling derrick and its pedestal, and get the first ten steps natural frequency and mode shape, observing its calculated displacement and equivalent stress, get the vibration characters of JJ113/32 workover rig derrick.Through static and modal analysis, get the part of stress concentration of derrick, and advanced the structural of dangerous section, avoid the emergence of weak structural.Accessing to research the security identification theory seriously, this paper identify the security of JJ113/3 workover rig derrick which is using now, and get the security level.