在侧钻开窗过程中,选择动力钻具、确定钻压和转速等参数的重要依据是铣鞋在开窗过程中的受力状态。建立套管-铣鞋的相互作用模型,并编制计算程序对铣鞋受力情况进行分析,获取不同施工参数(如钻压、切入角度和转速)对开窗铣鞋的受力和钻进速度的影响;并进行多组套管开窗实验验证所建立套管相互作用模型以及仿真结果的正确性。结果表明:在整个开窗过程中,随着铣鞋铣入套管的深度加深,侧向力逐渐变小,变为0后反向增加;钻压越大铣鞋上的扭矩和钻进速度越大;切入角度越大铣鞋上的侧向力和扭矩越大。
In the process of windows milling for sidetrack drilling, whether the selected motor matches the milling tool or the mill, and whether the drilling parameters designed, such as the weight on mill (WOM) and rotation speed, can meet job re-quirements are factors to be considered. It is important to make these choices based on the forces and torques applied on the mill. A mechanical analysis model was described, which simulated the interaction between the mill and casing and was used to analyze the force on mill. A software was developed for the mechanics analysis of the mill, and to study the effects of dif-ferent operating parameters, such as WOM, cutting angle and rotation speed, on the force and torque acted on the mill and the rate of penetration (ROP). In addition, various experiments were conducted to verify the mechanical analysis model and the simulation results. During the process of window milling on casing, the lateral force tends to gradually reduce, and after it reduces to zero, it will then gradually increase in the opposite direction. With the increasing milling depth into the casing, the greater WOM can cause the greater torque and ROP, and the greater of the cut angle, the greater the lateral force and torque are required.