Synthesis and laboratory testing of a novel calcium-phosphonate reverse micelle nanofluid for oilfield mineral scale control

Abstract

Mineral scale blockage is a severe challenge to the oil and gas industry. Scale inhibitors are routinely injected (squeezed) into downhole formation to control the scale threat. Other than the conventional aqueous scale inhibitor products, non-aqueous inhibitor packages are more suitable for certain low water cut and water sensitive production wells. In this study, a novel reverse micelle based inhibitor nanomaterial fluid (nanofluid) was prepared to serve as a non-aqueous scale inhibitor delivery vehicle. The nanofluid was prepared by mixing component micelle solutions at room temperature to form scale inhibitor nanomaterials. The physicochemical properties of the prepared inhibitor nanomaterials, morphology, skeletal structure and thermal decomposition, were evaluated by electron microscopy, infrared spectra and thermal gravitational analyses, respectively. The transportability of the inhibitor nanofluid was investigated via column flow-through tests. Results show that the nanofluid is transportable in a calcite medium. Furthermore, preflush solutions can impact the nanomaterial transport behavior and an organic preflush is observed to enhance the nanofluid transport compared with aqueous solution preflush. The potential field application of this reverse micelle inhibitor nanomaterial product was assessed via laboratory squeeze simulation studies. The results suggest that this non-aqueous inhibitor nanofluid exhibits an enhanced performance compared with the conventional acidic pill solution in terms of extending the squeeze lifetime. This is the first report of the synthesis of reverse micelle based scale inhibitor nanofluid and the investigation of the transport and return behavior of this product for the purpose of oilfield scale control.