Saturation Index Prediction Based on Taguchi Approach and Multiple Linear Regression in Oil Wells

During the productive phase of an oil well, there may be jointly production of groundwater, called formation water, which has different dissolved salts which may, during production, form a solid phase (precipitate), causing partial or total obstruction of the well, due to scaling of precipitation. The main inorganic scales in oil industry are: calcium sulfate (CaSO₄), barium sulfate (BaSO₄), strontium sulfate (SrSO₄) and calcium carbonate (CaCO₃). The carbonate is precipitated due to changes in temperature, pressure and water flow associated with oil. These variations happen due to fluid displacement which originally are in equilibrium conditions to the flow conditions. As the removing process is extremely expensive and often irreversible, mathematical tools are used to predict the saline scale. This work will present three methods: software Multiscale, Multiple Linear Regression and Taguchi Approach. Those methods will help predict saline scales of CaCO₃, by calculating saturation index. The other salts will not be used in this monograph. After realization of the experiments, comparing the values found in the calculation of the CaCO₃ saturation index using the three methods, satisfactory results are obtained when the pressure ranges up to 20% of the experimental pressure, with a reduction in the number of experiments, using the method known as Taguchi Approach.