Causes Analysis of Eccentric Wear of Sucker Rod in Produced Fluid with Polymer

Abstract:

After polymer flooding was put into effect in DaQing oilfield, eccentric wear of sucker rod and tubing has been so serious that it made the rods break. This is because production liquid produced from normal wells is pure viscous fluid while liquid produced from polymer flooding oil wells is viscoelastic fluid. The flow equation of viscoelastic fluid in eccentric annulus was established in cylinder coordinate system, and the velocity distribution was solved. Based on upper-convected Maxwell constitutive equation, the normal stress calculating model of viscoelastic fluid acting on sucker rods was established. The normal stress of viscoelastic fluid acting on inner rod in eccentric annulus was measured under different experimental conditions indoors. The result proves that normal stress is the main reason of eccentric wear.

• Periodical: Advanced Materials Research (Volumes 594-597)
• Pages: 2744-2747
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.594-597.2744
• Online since: November 2012
• Authors: Bao Jun Liu, Cai Xia Fan, Hong Du
• Keywords: Eccentric Wear, Normal Stress, Viscoelastic Fluid

References

[1] Shifang Han: Constitutive Equation and Computational Analytical Theory of Non-Newtonian Fluids (Science Press, China 2000)

[2] Wenquan Tao: Numerical Heat Transfe (Xi'an Jiaotong University Press, China 1995).

[3] H.S. Han, D.M. Wang and L.P. Guo: ACTA PETROLEI SINICA. Vol. 25 (2004), p.92 (in Chinese)