Study And Manufacture Of Traveling Block Type Workover Derrick

At present, the most of derricks the oilfield used are BJ-18 workover derricks. This kind of wokeover derrick hasn't been improved for dozens of years, it exposes some questions and defects during its using.1.The technology of BJ-18 derrick is behindhand,the rated lifting load and the maximum lifting load are low, it can't meet the demand of operation. The beam is easy to be deformed, the inclined-drag joint can be creaking and crooked.2.The function of BJ-18 derrick is single, the efficiency is low. Each time when change the wellpoint, it needs to passing line.Time and again the traveling block system falling and lifting makes the derrick damaged in the early time, the efficiency is difficult to improve. When using this kind of derrick ,the operations must climb the derrick and work in high altitude,the hidden danger of accident is increased.3.The design of the structure is unreasonable. In thr course of rising and falling the tubing, the derrick is apt to colliding the beam, causing partial damage of derrick.Based on the investigation of on-using derricks and the wide technological interflow with the users, the structure of the derrick is optimized. A new type of overwork derrick is designed. The traveling block system and crashworthy installations between crown blocks are added. And the weak parts are strengthened. By using the finite element software(ANSYS), the static mechanical bahavior, dynamic response and stability of the derrick are analysed and calculated. And a series of calculations about the internal force, displacement and safety coefficient are carried out. The result of the calculation shows that the total stability of the derrick is satisfied, and the intensity is high enough.At present, this kind of derrick has been popularized in the oilfield. The efficiency is improved.