Buckling and lockup of tubulars in inclined wellbores

Journal Article · Fri Sep 01 04:00:00 EDT 1995 · Journal of Energy Resources Technology

DOI:https://doi.org/10.1115/1.2835342· OSTI ID:122690

Wu, J ^[1]; Juvkam-Wold, H C ^[2]

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1. Maurer Engineering Inc., Houston, TX (United States)
2. Texas A and M Univ., College Station, TX (United States)

This paper studies sinusoidal and helical buckling of tubulars in inclined wellbores and the ``lockup`` of tubulars due to buckling. The results show that tubular buckling starts from the tubular bottom in low-inclination wellbores, where the axial compressive load is largest due to tubular weight. In high-inclination wellbores it may start from the top portion of the tubular, where the axial compressive load is largest due to frictional drag. This clarifies the confusion on whether or not the tubular buckles at once on it entire length in inclined wellbores. New sinusoidal and helical buckling load equations are presented to better predict tubular buckling in inclined wellbores (0--90 deg). The lower the wellbore inclination angle, the smaller the axial compressive load required to initiate tubular buckling. However, a certain nonzero axial compressive load is still needed to buckle the tubulars in vertical wellbores. When tubulars buckle helically, a large wall contact force will be generated, and the ``slack-off`` weight at the surface will not be fully transmitted to the tubular bottom due to large resultant frictional drag. The ``lockup`` of tubulars may even occur, where the tubular bottom load cannot be increased by slacking-off weight at the surface.

• Sponsoring Organization: USDOE
• OSTI ID: 122690
• Journal Information: Journal of Energy Resources Technology, Journal Name: Journal of Energy Resources Technology Journal Issue: 3 Vol. 117; ISSN 0195-0738; ISSN JERTD2
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
42 ENGINEERING
COMPRESSION STRENGTH
DEFORMATION
DIRECTIONAL DRILLING
DRAG
DRILL PIPES
EQUATIONS
FRICTION FACTOR
INCLINATION