Calculating Scaling Tendency and Scaling Index to predicting the formation of mineral deposits in the oil field

Samira Heidari¹ Freidun Esmaeilzadeh²

1) Iran, Shiraz university, School of Chemical and Petroleum Engineering
2) Iran, Shiraz university, School of Chemical and Petroleum Engineering

Publication : International Conference On Research Science And Technology(restconf.com)
Abstract :
Water injection process as one of the known methods has many applications in the oil industry either as pressure keeper or as enhanced oil recovery method. One of the main problems in the water injection process is incompatibility problem of injection water with formation water. It causes depositions that have great effect on the oil recovery operation. In this study the incompatibility between formation water from one of the Iranian oil reservoirs and injection water that is candidate for injection was examined. Oddo and Tomson model (1997) was used to predicting the probability of formation of deposits of sulfate and carbonate salt as two important salts in the oil field. Temperature range (35–80 °C) and pressure range (14.7-3500 Psi) were examined. Results showed that increasing ionic strength can increase the solubility of salts. Also, incompatibility between injection water and formation water had more effect than changing thermodynamic conditions on forming sulfate salt deposits. Based on calculated saturation index of salts, there were not significant depositions at surface conditions (25°C, 14.7 Psi). But, at high temperature and pressure (80-110°C, 2000-3500 Psi) there were ability of the formation of barium and calcium sulfate sediments.
Keywords : Water Injection Incompatibility Deposition Scaling Tendency Scaling Index