Effects of expansion rate on plasticity and structural integrity of downhole tubular

Abstract The current work presents an investigation of the effects of expansion rate on plasticity and structural integrity of down-hole solid tubular. Down-hole tubular has proven itself to be a promising technology in oil well applications by providing optimum solutions for many issues. One of the challenges still facing researchers and field engineers in implementing and making down-hole tubular technology cost effective is to conserve structural integrity of tubular. Cold expansion affects mechanical properties and induces residual stresses in tubular, hence reduces its collapse, burst, and fatigue ratings. The knowledge of properties variation is required in correctly predicting life span of tubular under given operational conditions. In present work, cold expansion of tubular under down-hole conditions is experimentally and numerically investigated at different strain rates. Strain rates are varied by changing the velocity of mandrel that is used to expand the tubular. Firstly, different tubular expansion experiments are performed to achieve 16%, 20%, and 24% expansion ratio. Secondly, finite element model of tubular expansion is developed in commercial finite element software ABAQUS. Simulation results are found to be in good agreement with experimental observations. Finally, further simulations are performed to thoroughly analyze the effects of expansion rate on the deformation behavior of tubular. It is found that there is variation in contact pressure at tubular-mandrel interface, effective stress, equivalent plastic strain, and thickness reduction during expansion process. These variations ultimately influence post-expansion properties of tubular particularly collapse and burst strengths, and hence its structural integrity. However, length shortening has marginally affected by expansion rates.

[1]  Brian N. Leis,et al.  Evaluation of burst pressure prediction models for line pipes , 2012 .

[2]  Tasneem Pervez,et al.  Solid Tubular Expansion in Horizontal Wells , 2007 .

[3]  Mark K. Adam,et al.  Testing Methodology for the Preliminary Assessment of Mechanical Performance of Materials for Expandable Applications , 2010 .

[4]  Lizhong Wang,et al.  Plastic collapse analysis of thin-walled pipes based on unified yield criterion , 2011 .

[5]  Tasneem Pervez,et al.  Simulation of Solid Tubular Expansion in Well Drilling Using Finite Element Method , 2005 .

[6]  Stelios Kyriakides,et al.  Collapse of partially corroded or worn pipe under external pressure , 2008 .

[7]  Yuung-Hwa Lu,et al.  Study of tube flaring ratio and strain rate in the tube flaring process , 2004 .

[8]  Tasneem Pervez,et al.  Use of SET in cased and open holes : Comparison between aluminum and steel , 2008 .

[9]  Richard Becker,et al.  Effects of crystal plasticity on materials loaded at high pressures and strain rates , 2004 .

[10]  Sarah B. Flaming,et al.  Understanding Post-Expansion Properties of Solid Expandable Tubulars , 2007 .

[11]  Liangchi Zhang,et al.  Constitutive modelling of plasticity of fcc metals under extremely high strain rates , 2012 .

[12]  Chris N. Carstens,et al.  Solid Expandable Tubular Technology: The Value of Planned Installation vs. Contingency , 2006 .

[13]  Rashid Khan,et al.  Experimental and Numerical Simulation of In-Situ Tube Expansion for Deep Gas Wells , 2012 .

[14]  Manfred Staat.  Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels , 2005 .

[15]  Wang Hui,et al.  Application of numerical simulation in the solid expandable tubular repair for casing damaged wells , 2009 .

[16]  T. Pervez,et al.  Experimental and numerical investigation of expandable tubular structural integrity for well applications , 2010 .

[17]  R. D. Mack,et al.  The Effect Of Tubular Expansion On The Mechanical Properties And Performance Of Selected OCTG - Results Of Laboratory Studies , 2005 .

[18]  H. S. Kushwaha,et al.  Some recent developments on integrity assessment of pipes and elbows. Part II: Experimental investigations , 2006 .

[19]  F. J. Klever,et al.  Analytical Burst Strength Prediction of OCTG With and Without Defects , 1998 .

[20]  Jun Agata,et al.  An Experimental and Numerical Approach to the Prediction of Collapse Resistance for Expandable Tubulars , 2010 .

[21]  Keith K. Millheim,et al.  Applied Drilling Engineering , 1986 .

[22]  Gerry Cales,et al.  Subsidence Remediation - Extending Well Life through the Use of Solid Expandable Casing Systems , 2001 .