Analysis and modeling of buckling in drillstrings

Abstract

The primary objective of this project, in a collaboration between the mechanical engineering and development laboratory “LGMD-ENP” and the development and research center “SONATRACH”, is to analyze the buckling problem for drill strings constrained within wellbores, a mechanical failure phenomenon that causes increase in torque and drag loads that can jeopardize drilling operations. First, we make a comparative study of the different models for the critical loads causing buckling to provide insight into the preventive measures need to be taken. Then we use the Lubinski model to identify the post-buckling shape of the drill string within vertical wells. For inclined wellbores, the equilibrium equations are established to determine the bending moment along the drill string and last simulations are run using WellScan software to investigate the effect of drilling parameters on the phenomenon via hypothetical and real case studies provided by a drilling field in Hassi Messaoud.