Onset of drillstring precession in a directional borehole
This paper presents a mathematical procedure for the determination of drillstring precession in a directional borehole and stability of drillstring rotation constrained by borehole geometry. The conditions are found when the energy of axial vibrations is transformed into energy of transverse vibrations. Under these conditions the drillstring rotation around its axis becomes unstable and the transition to the rotation around borehole axis, i.e. precessional motion, takes place. The conditions are formulated in terms of rotary speeds, amplitude of weight-on-bit vibrations, damping and geometry. A finite element procedure reduces the partial differential equation describing drillstring dynamics to a set of Mathew-Hill ordinary differential equations. The boundaries of parametric resonances for these equations determines the onset of precessional motion of the drillstring. The results can be used to predict stable performance of drillstrings during directional drilling operations.
- Research Organization:
- Sohio Petroleum Co.
- OSTI ID:
- 6042603
- Report Number(s):
- CONF-8409104-
- Journal Information:
- Soc. Pet. Eng. AIME, Pap.; (United States), Journal Name: Soc. Pet. Eng. AIME, Pap.; (United States) Vol. SPE13027; ISSN SEAPA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
020300* -- Petroleum-- Drilling & Production
DIFFERENTIAL EQUATIONS
DIRECTIONAL DRILLING
DRILL PIPES
DRILLING
DRILLING EQUIPMENT
EQUATIONS
EQUIPMENT
FINITE ELEMENT METHOD
FORECASTING
MECHANICAL VIBRATIONS
MOTION
NUMERICAL SOLUTION
OIL WELLS
ORIENTATION
PERFORMANCE
PIPES
ROTATION
STABILITY
WELLS