基于SPH-FEM耦合算法的膨胀管磨铣动力学分析OA

In casing-damaged wells repaired with expandable liner patching,the patched section tends to deform under formation pressure,causing wellbore shrinkage and subsequent stuck drilling incidents that disrupt production.Milling the expandable liner becomes necessary to restore the wellbore diameter.The milling process exhibits strong nonlinear characteristics in the dynamic contact between abrasive grains and the expandable liner,while chip separation and movement involve complex fracture and flow behaviors.Significant challenges arise from large deformations,material removal,and mesh distortion.To address these issues,this study developed a milling dynamics model and a numerical simulation method using a coupled SPH-FEM algorithm,incorporating the expandable liner,casing,cement ring,and abrasive shoe.Comparison with experimental data showed an 8.29％error in grinding force,validating the model's accuracy.Dynamic analysis of multi-pass milling under constant depth revealed that a 4-pass milling strategy reduced the peak equivalent stress in the expandable liner by 29.70％and decreased grinding force by 63.90％,effectively mitigating bit sticking and drilling jamming risks.