Sensing and computational frameworks for improving drill-string dynamics estimation

In this paper, we consider the axial motion of a directional multi-sectional drill-string. The drill-string dynamics are represented by distributed dynamical model (wave equations) coupled with an ordinary differential equation at downhole boundary (bit-rock interaction). interaction between drill-bit and rock can introduce severe vibrations in result safety performance issues. Consequently, drilling is interwoven our knowledge subsurface. To address these problems, propose sensing computational framework for estimating specific intrinsic energy rocks while drilling. By exploiting derived models’ particular structure, combine modeling top-drive hook-load (force) hook-speed (velocity) measurements to estimate force-on-bit without requiring sub-surface. Then, record seismic radiation patterns interactions near surface (i.e., drilling). Such idea allows deriving appropriate estimation rocks’ We two alternative property algorithms based on direct parameter machine learning concepts complete analysis. different approaches tested validated simulations. discuss their respective advantages drawbacks. Finally, show how extend methodologies presence non-linear Coulomb friction terms axial–torsional oscillations.