Hydraulics Optimization For Efficient Hole Cleaning in Deviated and Horizontal Wells

Abstract

Abstract Efficient cuttings transport and hole cleaning is a very important factor that must be considered during drilling operations. In inclined and horizontal drilling, hole cleaning is a common issue since there is high tendency for formation of cuttings bed in the hole which can lead to several complex problems. The optimization of cuttings transport depends on so many factors like hole angle, cutting size, drill string rotation, drill pipe eccentricity, bit hydraulics etc. This paper is designed to examine critical factors that affect the efficient cleaning/transport of cuttings and bit hydraulics in inclined wells with a view to understanding how to minimize drilling difficulties thereby reducing non producing time (NPT) during drilling operations. The developed model ensures proper hole cleaning in the critical hole angle (between 45° and 60°) as well as horizontal wells and determining the optimum flowrate and rate of penetration (ROP) that will ensure successful drilling. The model also helps to save time wasted when we encounter problems of high concentrations of cuttings which causes high Equivalent circulation density (ECD) that can result in lost circulation problem amongst others. Finally, the developed model is validated using field data and graphs showing how the penetration rate increases as cuttings concentration in the annulus reduces thereby optimizing drilling operations.