A biodegradable scale inhibitor for oil well application

Ascorbic acid, an easily biodegradable natural product with an excellent environmental profile, was studied in an oil well downhole condition for inhibiting calcium carbonate scale deposition. Scale inhibition efficiency studied in artificial seawater and formation water mixtures of various proportions through static jar test and dynamic tube blocking tests show its calcite scale inhibition potential at high-temperature wellbore conditions. Investigation made through scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and Fourier transform infrared spectrometry revealed severe structural anomalies of CaCO₃ crystals and explain the scale prevention mechanism. Its biodegradation rate studied using a UV-visible method in a marine environment is excellent and meets environment requirements. In a sensitive marine environment, ascorbic acid could be deployed as an excellent green chemical for continuous injection into the wellbore to prevent carbonate scale deposition.