Abstract

A drill string is a slender structure with nonlinear dynamics; it is an equipment used in the oil industry to drill rock in the search of oil and gas. The aim of this paper is to model the uncertainties related to the speed imposed at the top and uncertainties related to the bit-rock parameters, and to investigate how these uncertainties propagate throughout the system. The continuum system is linearized about the prestressed configuration, the finite-element model is applied to discretize the system, and then a reduced-order model is constructed using normal modes of the linearized system; only torsional and axial vibrations are considered in the analysis. A constant rotational speed is imposed at the top and a nonlinear bit-rock interaction acts at the bottom. A probabilistic approach is used to model the uncertainties and the Monte Carlo method is used to approximate the stochastic differential equations.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.