|
| Gap-element Method of Three-dimension Contact Problem for Drillstring in Horizontal Well |
| |
| View Full Text View/Add Comment Download reader |
| DOI：10.7511/jslx19924064 |
| KeyWord:horizontal well, drillstring, contact problem, gap-element method, |
| Zhang Xuekang Liu Jubao |
|
| Hits: 1381 |
| Download times: 0 |
| Abstract: |
| The contact between drillstring and bore hole wall in the process of horizontal drilling is of large area and geometrically nonlinear. Considering both wall and drillstring, the Multidirectional Contact Gap Element (MCGE) is presented in this paper in order to make it easy to correctly describe the contact state, which also contributes to avoiding the global stiffness matrix singularity that often appears when using normal finite element method. Using the method recommended by this paper, we can make a thorough analysis of BHA (bottom hole assembly) or the whole drillstring. Through Euler-Modified Newton iteration, we can get the mechanical deformation of a drillstring at bit, which is very important for the control of the hole trajectory.The result of numerical calculation provided by this paper is satisfactorily agreed with that of field test in terms of prediction of hole trajectory and evaluation of BHA. Therefore it is practically important for the increase of drillstring efficiency and the guarantee of drilling quality. |
|
|
|