Study On Dynamic Characteristic Of Double Elevating Drilling Rig Derrick And Substructure

Current years, the advantages of K-derrick are accepted by more and more users, self elevating substructure is also replacing others, such as box on box , raised floor substructure and so on. The derrick and substructure in the thesis are made up of K-derrick and self elevating substructure. Its prominent characteristic is that the derrick is placed on the substructure. It can install at low place and elevate all together because derrick and substructure can be puckered at primary place. In addition, it has the merits of convenient installation, transportation and quick use. The thesis is considered project practice full at the base of existing study and studys static and dynamic characteristics of double elevating drilling rig derrick and substructure. The aim of the thesis are to search weak places and hidden troubles, to supply academic criterions for drilling well tasks, to avoid accident happening and to develop analysis theory of derrick and substructure.Finite element model is built according to the actual structure of double elevating derrick and substructure and is carried on static analysis according to three kind of work situations using the finite element software ANSYS to obtain the stresses and displacements. Modal analysis is one of new ways on dynamic characteristic researchs, and now becomes the core of dynamic analysis and design in modern engineering. Natural frequencies and modes of vibration of structure resulted from modal analysis are the important parameters on dynamic design of structure. So it is the start of all dynamic analysises as transient analysis. This thesis completes the mode analysis of rig derrick and substructure by the finite element software, getting the free frequencies of preceding 10 steps and vibration modes. Observing displacements and stresses, we get their vibrational characteristics.The thesis mainly completes the transient analysis and dynamic response calculation. It obtains the datas of drilling well places for many times in order to get the value of hook loads and establishes the modal of logarithmic normal distribution at hook loads as statiscic variables. The thesis establishes the load spectrum in programme of dynamic study. It completes transient analysis at normal work state and gets the rules of time responses in different orientation.