A Two-Region Hydraulic Averaging Model for Cuttings Transport During Horizontal Well Drilling

摘要

The two-region hydraulic averaging model was used to analyze the problem of cuttings transport during horizontal well drilling. This model considers a two-phase two region system composed of a moving bed (ω-region) and a stationary bed of drill cuttings modelled as a porous medium (η-region). The co-region is made up of a solid phase (σ-phase) dispersed in a continuous fluid phase (β-phase), while the η-region consists of a stationary solid phase (σ-phase) and a fluid phase (β-phase). The volume averaging method was applied to obtain the volume-averaged transport equations for both the moving bed and the porous medium regions. These equations are based on the non-local form of the volume-averaged momentum transport equation that is valid within the interface region. The three main flow patterns of the horizontal cuttings transport process analyzed were: Case 1 - fully suspended flow, Case 2 - flow with a stationary bed and Case 3 - flow with a moving bed. The one-dimensional models for all cases were solved numerically using the finite difference technique with an implicit scheme. The numerical results were compared with experimental data and theoretical results reported in the literature and a good agreement was found.