With the ever-increasing measured depths and horizontal displacements in ex
tended-reach (ERD) wells,good hole cleaning remains a major challenge. Rece
ntly a hole cleaning model for fluids in laminar flow was presented to the
industry. Since its introduction, the model has been used on many occasions
to characterize hole cleaning efficiency in post-well analysis, evaluate f
luid performance during the drilling of ERD wells, and to predict fluid rhe
ological properties and pump output levels for optimum cleaning in prewell
planning. In this paper, four field applications of the hole cleaning model
ing in ERD and deviated wells are discussed. In these cases, the hole clean
ing model was used to predict intervals of hole cleaning problems and ident
ify certain ranges of fluid rheological properties that promoted good clean
ing.