Finite Element Analysis And Calculation Of K-type Derrick

Derrick is one important component of the oil rig,which plays an important role in hanging the various drilling, enduring the various loads in the drilling process and tying together drill drill into the target zone during the drilling.The safety, reliability and stability of derrick have been concerned to people, therefore, analysis of the strength, modal and stability were the essential part during procedure of production and design process.Accurately analyse the force of the derrick can prevent accidents, reduce personnel and loss of property.In this paper, the K-type derrick which endures 225 tons of hook was took for an example.First, the derrick was discreted into dimensional beam elements ,and the three-dimensional finite element model was established by the finite software .And then, the force and deformation of the derrick in the case of endure maximum hook load and the dead weight ,the sate of Lifting conditions(include the lifting angle of 0,15 and 45 ), the dead weight and maximum hook load (no pipe setback,full pipe setback).The results show that:the four conditions can meet the strength demand,and the most dangerous state is the state of the largest hook load with the wind load while no pipe setback, which strength safety factor is 1.64. Finally, in order to obtain the buckling load factor, a total stability analysis was took to the derrick, they are respectively with the value of 4.9553,5.6988,7.3316,7.6551,8.5997.Through the computation, the first instability load is 1114.9 tons, while the largest hook load of derrick is 225 tons,which meets the derrick stability requirements. It shows that the stability of the derrick is higher then the specific strength reserves,that is to say that the first occurrence of damage to the derrick is due to the strength, rather than the overall structure of the instability. The derrick in the normal design conditions meets the strength and stability conditions, and it can Safely work.