Hydraulics Optimization For Efficient Hole Cleaning in Deviated and Horizontal Wells

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.

CFD Method for Predicting Annular Pressure Losses and Cuttings Concentration in Eccentric Horizontal Wells

“…It is believed that, cuttings transported in the annulus are not always affected by a single parameter, but a combination of parameters to ensure efficient hole cleaning [4]. Other studies have also confirmed that increase in fluid velocity results in a decrease in cuttings accumulation in the wellbore [5][6][7]. Ozbayoglu and Sorgun [8] also conducted cuttings transport experiment and developed empirical correlations for estimating pressure losses with the presence of cuttings and drill pipe rotation in horizontal and inclined wellbores.…”

Optimization Of The Drilling Parameters In Low Angle Wells By The Application Of Statistical Analysis

“…Ogunrinde y Dosunmu, (2012) developed a model that ensure an appropriate hole cleaning in the critical inclination interval (45° -60°) and was determined the optimal flow and ROP to reach a successful drilling [2].…”

Contributory Influence of Drill Cuttings on Equivalent Circulation Density Model in Deviated Wellbores

“…One of these problems is that offered by the mud in its contact with the wellbore and other well elements such as casing, DP, DC and other drilling jewelries [1]. ECD results from the circulation of DM in the wellbore [2][3] during pumping operations. ECD is a measure of the ABHP that is exerted on the formation during any drilling, completion or workover operations.…”