Numerical evaluation of clayey soil under jetting procedure using Lattice Boltzmann Method

Resumo

Offshore operations in deep and ultra-deepwater increasingly demand usage of different well
construction methods. Regarding a well casing system, the conductor installation by jetting is one of the adopted
techniques in top hole operations in these scenarios. In a deepwater environment, marine soil is cohesive,
presenting mud characteristics and low shear strength. Consequently, from a mechanical perspective, those soils
behave as a combination of an elastic solid and viscous fluid. Thus, the use of fluid rheology by Herschel Bulkley’s
constitutive equations to analyze it is a valid approach. Numerical modeling stands out as an interesting choice for
analysis of jetting problems due to its accuracy and affordable cost of development in the design phase. The Present
work investigates soil response under high shear rates from a vertical jet. The numerical simulations are performed
based on the Lattice Boltzmann Method (LBM). We perform parametric analysis of rheological parameters of the
soil as yielding viscosity and yield stress. Results show that soil behaves in an increasingly structured way by
increasing the values for the yield stress and the yielding viscosity, demanding higher jet speeds or longer jetting
time in order to drill larger depths.