Laboratory modeling of pipe column deformation in curvilinear well bore section

Abstract

The objective of this work is development and manufacturing of test bench for experimental research of spatial
elastic deformations of pipe columns in conditions, which imitate wells with arbitrary axis curvature.
Basic principles of similarity theory were used for accordance between model and reality of pipe column and
well bore. Force, length and time were chosen as basic units of measurement. Pipe column length; weight of length
unit; axial force, which loads pipe column; flexion stiffness; free fall acceleration; force moment in pipe column
cross-section and normal stress in pipe column cross-section were chosen as basic parameters of mechanical system.
Four criteria of similarity between model and reality, especially length, force, force moment and stress were
written for seven basic parameters of mechanical system and basic units.
Model of drill string section, which consists of drill pipes with external diameter 127 mm, was made, using
similarity theory. Copper pipe filled by weighing material, which consist of iron and plumb shot in proportion
0,88 / 0,12 was used as mechanical model. Laboratory test bench was designed and made for ensuring of influence of external load on model deformation. This laboratory test bench secures: load on model by axial force and torsion
moment; imitation of well bore with spatial axis curvature.
The developed similarity criteria and laboratory test bench can be used for analysis of pipe columns intensedeformed
state in curvilinear well bore sections. Especially in cases, when analytical modeling is impossible to use.
For example, when inclination and direction angles of well bore are simultaneously changed with very high rate.