Abstract
Efficient hole cleaning in drilling operations is essential to ensure optimum penetration rates. This complex problem involves the simultaneous analysis of multiple parameters, including cuttings characteristics, fluid rheology, and annulus space geometry. The effect of the mud density increase due to the cuttings concentration, which itself is a function of the settling velocity and rate of penetration (ROP), must be considered for accurate calculations of the equivalent circulation density (ECD). Mechanical Specific Energy (MSE) models have been widely used in bit selection, drilling efficiency quanti-fication, drilling performance monitoring, drilling performance optimization, and ROP improvement. We attempted to employ MSE for optimized hole cleaning and controlled ECD. Cuttings concentration was integrated with the drilling MSE, which was calculated to determine the effect of different drilling parameters on hole cleaning and ECD. We proposed a new model for predicting the ECD in vertical and deviated wellbores that takes fluid and formation properties, as well as wellbore and drill string geometry and drilling operational parameters, into account. The model predicts the cuttings concentration and equivalent circulation density in vertical and deviated wells. The workflow implements the critical and settling velocity models, which aids in optimizing drilling performance and hole cleaning. The developed model was used to study the effect of different drilling parameters on ECD and help engineers optimize their operational parameters. Integrating the drilling operational parameters to provide controlling options to drillers as they monitor ECD values while maintaining safety and optimizing the drilling job is critically important.
NSTL
Elsevier