Use of synthetic calcium carbonate particles as an additive in water-based drilling fluids

The design and formulation of drilling fluids are essential for a successful drilling operation performance. In this work, the incorporation of calcium carbonate particles (CaCO3) as a novel additive of water-based drilling fluids (WBMs) was evaluated. CaCO3 particles were synthesized by the precipitation method and characterized in terms of morphological, thermal and structural properties. WBM systems were prepared containing three different viscosifier additives such us xanthan gum, (XGD), guar gum (GG) or corona gum (GEC). The addition of CaCO3 particles on the rheological, filtration, thermal and structural properties of WBMs was investigated. It was found that fluids containing XGD and CaCO3 particles exhibited significant improvements on their functional properties. This behavior was mainly attributed to surface interactions between bentonite with polymers, as well as bentonite with CaCO3. For all systems, the addition of particles resulted in a reduction in the volume of filtrate. Moreover, the Sisko and Herschel Bulkley model were employed in order to describe theoretical the rheological behaviour.