Sensitivity Analysis Of Oil Derrick And The Application In The Optimum Sensor Placement

The oil derrick is one of the indispensable equipment in the process of oil exploration and exploitation, the suspension on the block, hook, platform and other professional tools, its safety relates to the safe production of the whole oil-field. Static/dynamic sensitivity analysis of the derrick, can provide theoretical basis and practical way for derrick maintenance, test, and safety evaluation, also can provide the basis for the state of the derrick real-time detection, to prevent derrick safety accidents. This paper introduces the structure sensitivity analysis theory and sensitivity analysis method based on the ANSYS software; according to different damage defects existing in the derrick, put forward the suitable equivalent method; take JJ220/42-K type derrick as an example, analyzes the static/dynamic sensitivity to derrick damage defects; according to the results of sensitivity analysis to optimize the position of stress, frequency and vibration mode sensors when the derrick is overall damage.First, introduces the calculation method of structure absolute sensitivity and relative sensitivity, summarizes the main steps of the sensitivity analysis based on ANSYS optimization design, and introduces the optimum design of first-order optimization algorithm. Established JJ220/42-K type derrick finite element model. Equivalent treatment overall damage(overall bending, eccentric load and foundation subsidence) and partial damage(corrosion, bar bending and node rigid reduce) of the derrick exist.Second, Analyzes the static/dynamic sensitivity of the JJ220/42-K type derrick. Analyzes the absolute sensitivity and relative sensitivity of the displacement, stress, frequency and modal displacement of the JJ220/42-K derrick model to the overall damage defects(overall bending, eccentric load and foundation subsidence) and partial damage(bar corrosion, bar bending and node rigid reduce). Get the biggest effect of the static/dynamic damage defect types of derrick.The end, Illustrate with example the sensitivity analysis of optimal placement of the sensor used in the derrick. Optimize the position of sensors when there is a whole damage defects of derrick application of the result of the analysis of derrick static/dynamic defects to the damage of the absolute sensitivity and relative sensitivity. Determine the optimized layout of stress strain sensor and frequency sensor and vibration sensor when the existing overall damage defects of the derrick was overall sine initial bending, load eccentricity, base settlement.