Investigation of hole cleaning parameters using computational fluid dynamics in horizontal and deviated wells

The need for technologies to reduce cost and improve recovery from existing hydrocarbon reservoirs is well established. One of the most effective methods of cost reduction relies on improvement of drilling technologies. Particularly, understanding the parameters that control hole cleaning is beneficial especially in both horizontal and deviated wells. For this purpose, a section of casing-drill pipe annulus section was simulated using Computational Fluid Dynamics to determine the effects of fluid velocity, cutting size, rate of penetration, drill pipe rotation and inclination angle in deviated wells. The Eulerian Model Simulations were conducted at steady state and the results of the data collected for maximum cutting concentrations in the annulus were graphically analyzed. Formation of cutting beds is noticed near the entry section of the annulus and the transport of the cuttings in the annular section occurs in the form of stratified flow. Fluid flow rate, angle of inclination and rate of penetration have a major impact on cutting concentrations and proper prediction of these parameters are important to avoid formation of cutting beds. It is also noted that drillpipe rotation can enhance cutting transport but it generally has a greater effect on smaller sized particles