Keywords: nanomaterials, rheology, drilling, oilwell
Summary:Increasing global energy demand has been forcing operators to drill and produce from high pressure, high temperature (HPHT) wells. Some of the important roles drilling fluids (muds) must play are removal of cuttings, lubricating the drill bit, maintaining the stability of the wellbore and preventing the inflow-outflow of fluids between the borehole and the formation. There are two types of wellbore fluids being used during the drilling process, non-aqueous muds, and water-based muds wherein a higher specific gravity material (barite) is added to densify the fluid, which balances the bottom-hole pressure and prevents the influx of gas and fluids from the earthen formation into the wellbore. One of the most significant properties of drilling fluids that must be optimized is their capability to suspend solid components, both densifying materials and drilled earthen cuttings, to prevent density striation and associated challenges. In general, high temperature drilling environments result in thermal thinning of the drilling fluids, thereby potentially reducing suspension capability further. The suspension stability of drilling fluids has been improved through different approaches, including utilization of nanomaterials like graphenes. Nanomaterials has also been used as shale inhibitors, filtrate loss control and rheology modifiers. In this presentation, we will review the research works have been done towards the use of nanomaterials for drilling fluids and present some of our own laboratory work recently carried out on carbon-based nanomaterials.