Abstract

Poor hole cleaning remains one of the major concerns in oil and gas industry since it will induce expensive drilling problems such as stuck pipe, slow drilling rate, high torque and drag, lost control of density and poor cement jobs. Various drilling fluids have been widely used in the oil and gas industry to improve lifting capacity of drilled cuttings. In this study, the experiment was conducted using water based mud with Multiwall Carbon Nanotubes (MWNTs) additive to study its lifting capacity. The study focused on the amount of MWNTs used, cutting size and mud annular velocity effect on the mud lifting capacity.  The results show that lifted cuttings increase as the amount of MWNTs added increases. MWNTs associated with water based mud displays the stability against base mud since surface forces easily balance the gravity force and attached to drilled cuttings, resulting in increase of drag force acts to drilled cuttings and easily lifted cuttings to the surface. The MWNTs also will improve viscosity which will significantly increase carrying capacity of the mud. For small and medium cuttings, the improvement relatively simplified compare to the big cuttings. The impact will significantly increase as the annular velocity increase.

Key words:  Water based mud, lifting capacity, mud additives, drilled cuttings, mud viscosity.