The Effect of Drilling Fluid Rheological Properties on Hole Cleaning

Abstract

Abstract Hole cleaning is still among the most important problems to handle in drilling operations. The difficulty in removing cuttings bed during drilling arises because of the drilling fluid interacts with the cuttings in cuttings bed to form a cuttings bed gel. The drilling fluid composition can be designed to minimize the gel formation in the cuttings bed. At the same time the drilling fluid properties are optimized to ensure a sufficient shear stress on the cuttings particles to be able to remove the cuttings. This technique has been used in several of Statoil's drilling operations. The paper explains the effect of the cuttings bed properties on hole cleaning in detail. Furthermore, the paper demonstrates how the drilling operations were improved compared to earlier drilling operations using conventional drilling fluids. From drilling operations in North Sea fields it is shown how the total drilling progress is improved. The torque curves of comparable wells are shown. These curves demonstrate that a significantly improved hole cleaning have been experienced in the wells drilled with the drilling fluid made to minimize cuttings bed gel formation.