Estudos de métodos de avaliação da compatibilidade e do desempenho de inibidores de incrustação de sais inorgánicos.

Abstract

The demand for products derived from hydrocarbons is still currently being high, this demand has generated the need to increase and improve oil recovery methods. A widely used method is the injection of seawater, which naturally generates secondary effects such as the formation of saline scale. These scales build up and block equipment such as pipes and valves and can also damage the porous formation of the reservoir. Inhibitor injection is a method used to prevent the formation of scale, these chemical agents work by preventing nucleation and/or crystal growth. In this study, rapid methods of evaluating the compatibility and performance of three products were evaluated: Diethylenetriamine-pentakis(methylphosphonic acid) (DETPMP), Tritulyl phosphate (TF) and liquid from natural cashew nut shell (LCC). For the experiments, a model system was designed and assembled, with a 3D printed incrustation cell and a pressure variation data acquisition system. The compatibility experiments were carried out with the preparation of synthetic brines and the tests were carried out at a temperature of 90°C. The results were evaluated through turbidity analysis at different times. The optical microscopy technique was also used to visualize the formation of crystals and the effect that the products have on the size and shape of the crystals formed. In the evaluation of the inhibitors in the model system, it was observed that TF and DETPMP delayed the scale time, obtaining a time of 120 minutes for DETPMP and a time of 987 minutes for TF used at a concentration of 2000 ppm, TF being the inhibitor with the best efficiency. For the natural LCC, variation in the scale time was also observed; however, due to its low solubility in brine, the results were lower than synthetic inhibitors.