Three-dimension torque and drag mechanics analysis and implementation of full-hole drilling strings in extended-reach well

Torque and drag has great effect on design and operation of drilling extended-reach well, because of its characters such as long horizontal displacement, high deviation and long open holes, Prediction and control of torque and drag is a key technique of drilling an extended reach well successfully. According to the features of field drilling practice, by analyzing the force and deformation of the drill string, the three-dimension drag and torque calculation model suited to extended reach well is established using the spatial slanting plane. Finally, the software was developed using the models and methods issued in this paper, which got a good result in field application. The results show that the model has high accuracy and the precision of this model can meet actual requirement.