Influence of different minerals of sandstone rocks on the retention of scale inhibitor

Abstract An effective method for controlling scale formation near production wells is the squeeze treatment using a scale inhibitor. The scale inhibitor injected into the well is retained in the rock matrix and gradually released during the oil production, preventing scale formation. This study explored the interaction between a scale inhibitor, aminotrimethylene phosphonic acid (ATMP), and some mineralogical components of sandstone formations using batch experiments. The experiments were performed for each individual pure mineral phase (quartz, feldspar, kaolin, and biotite), as well as for combinations of these phases, in order to determine whether the retention curves for mixed systems may be derived from the curves of the individual constituents. Moreover, the impact of temperature and pH on the inhibitor retention mechanisms (adsorption and/or precipitation) was also evaluated. Biotite exhibited the highest retention among the evaluated pure minerals (70 mg/g), while aluminium released from feldspar and kaolin influenced retention through complexation with the inhibitor. These results emphasize the critical role of mineralogical composition in scale inhibitor retention and support the selection and formulation of more effective squeeze treatments in sandstone reservoirs.